The URL for Github Flavored Markdown documentation changed

This feature seemed to be the best analog to the previous page:
https://guides.github.com/features/mastering-markdown/#GitHub-flavored-markdown

Author: danhorst

versions/2.0.md

@@ -137,7 +137,7 @@ The object provides metadata about the API. The metadata can be used by the clie
 Field Name | Type | Description
 ---|:---:|---
 <a name="infoTitle"></a>title | `string` | **Required.** The title of the application.
-<a name="infoDescription"></a>description | `string` | A short description of the application. [GFM syntax](https://help.github.com/articles/github-flavored-markdown) can be used for rich text representation.
+<a name="infoDescription"></a>description | `string` | A short description of the application. [GFM syntax](https://guides.github.com/features/mastering-markdown/#GitHub-flavored-markdown) can be used for rich text representation.
 <a name="infoTermsOfService"></a>termsOfService | `string` | The Terms of Service for the API.
 <a name="infoContact"></a>contact | [Contact Object](#contactObject) | The contact information for the exposed API.
 <a name="infoLicense"></a>license | [License Object](#licenseObject) | The license information for the exposed API.
@@ -412,7 +412,7 @@ Field Name | Type | Description
 ---|:---:|---
 <a name="operationTags"></a>tags | [`string`] | A list of tags for API documentation control. Tags can be used for logical grouping of operations by resources or any other qualifier.
 <a name="operationSummary"></a>summary | `string` | A short summary of what the operation does. For maximum readability in the swagger-ui, this field SHOULD be less than 120 characters.
-<a name="operationDescription"></a>description | `string` | A verbose explanation of the operation behavior. [GFM syntax](https://help.github.com/articles/github-flavored-markdown) can be used for rich text representation.
+<a name="operationDescription"></a>description | `string` | A verbose explanation of the operation behavior. [GFM syntax](https://guides.github.com/features/mastering-markdown/#GitHub-flavored-markdown) can be used for rich text representation.
 <a name="operationExternalDocs"></a>externalDocs | [External Documentation Object](#externalDocumentationObject) | Additional external documentation for this operation.
 <a name="operationId"></a>operationId | `string` | Unique string used to identify the operation. The id MUST be unique among all operations described in the API. Tools and libraries MAY use the operationId to uniquely identify an operation, therefore, it is recommended to follow common programming naming conventions.
 <a name="operationConsumes"></a>consumes | [`string`] | A list of MIME types the operation can consume. This overrides the [`consumes`](#swaggerConsumes) definition at the Swagger Object. An empty value MAY be used to clear the global definition. Value MUST be as described under [Mime Types](#mimeTypes).
@@ -535,7 +535,7 @@ Allows referencing an external resource for extended documentation.
 
 Field Name | Type | Description
 ---|:---:|---
-<a name="externalDocDescription"></a>description | `string` | A short description of the target documentation. [GFM syntax](https://help.github.com/articles/github-flavored-markdown) can be used for rich text representation.
+<a name="externalDocDescription"></a>description | `string` | A short description of the target documentation. [GFM syntax](https://guides.github.com/features/mastering-markdown/#GitHub-flavored-markdown) can be used for rich text representation.
 <a name="externalDocUrl"></a>url | `string` | **Required.** The URL for the target documentation. Value MUST be in the format of a URL.
 
 ##### Patterned Objects 
@@ -578,7 +578,7 @@ Field Name | Type | Description
 ---|:---:|---
 <a name="parameterName"></a>name | `string` | **Required.** The name of the parameter. Parameter names are *case sensitive*. <ul><li>If [`in`](#parameterIn) is `"path"`, the `name` field MUST correspond to the associated path segment from the [path](#pathsPath) field in the [Paths Object](#pathsObject). See [Path Templating](#pathTemplating) for further information.<li>For all other cases, the `name` corresponds to the parameter name used based on the [`in`](#parameterIn) property.</ul>
 <a name="parameterIn"></a>in | `string` | **Required.** The ___location of the parameter. Possible values are "query", "header", "path", "formData" or "body".
-<a name="parameterDescription"></a>description | `string` | A brief description of the parameter. This could contain examples of use.  [GFM syntax](https://help.github.com/articles/github-flavored-markdown) can be used for rich text representation.
+<a name="parameterDescription"></a>description | `string` | A brief description of the parameter. This could contain examples of use.  [GFM syntax](https://guides.github.com/features/mastering-markdown/#GitHub-flavored-markdown) can be used for rich text representation.
 <a name="parameterRequired"></a>required | `boolean` | Determines whether this parameter is mandatory. If the parameter is [`in`](#parameterIn) "path", this property is **required** and its value MUST be `true`. Otherwise, the property MAY be included and its default value is `false`. 
 
 If [`in`](#parameterIn) is `"body"`:
@@ -891,7 +891,7 @@ Describes a single response from an API Operation.
 ##### Fixed Fields
 Field Name | Type | Description
 ---|:---:|---
-<a name="responseDescription"></a>description | `string` | **Required.** A short description of the response. [GFM syntax](https://help.github.com/articles/github-flavored-markdown) can be used for rich text representation.
+<a name="responseDescription"></a>description | `string` | **Required.** A short description of the response. [GFM syntax](https://guides.github.com/features/mastering-markdown/#GitHub-flavored-markdown) can be used for rich text representation.
 <a name="responseSchema"></a>schema | [Schema Object](#schemaObject) | A definition of the response structure. It can be a primitive, an array or an object. If this field does not exist, it means no content is returned as part of the response. As an extension to the [Schema Object](#schemaObject), its root `type` value may also be `"file"`. This SHOULD be accompanied by a relevant `produces` mime-type.
 <a name="responseHeaders"></a>headers | [Headers Object](#headersObject) | A list of headers that are sent with the response.
 <a name="responseExamples"></a>examples | [Example Object](#exampleObject) | An example of the response message.
@@ -1124,7 +1124,7 @@ Allows adding meta data to a single tag that is used by the [Operation Object](#
 Field Name | Type | Description
 ---|:---:|---
 <a name="tagName"></a>name | `string` | **Required.** The name of the tag.
-<a name="tagDescription"></a>description | `string` | A short description for the tag. [GFM syntax](https://help.github.com/articles/github-flavored-markdown) can be used for rich text representation.
+<a name="tagDescription"></a>description | `string` | A short description for the tag. [GFM syntax](https://guides.github.com/features/mastering-markdown/#GitHub-flavored-markdown) can be used for rich text representation.
 <a name="tagExternalDocs"></a>externalDocs | [External Documentation Object](#externalDocumentationObject) | Additional external documentation for this tag.
 
 ##### Patterned Fields
@@ -1201,7 +1201,7 @@ The following properties are taken directly from the JSON Schema definition and
 - $ref - As a [JSON Reference](https://tools.ietf.org/html/draft-pbryan-zyp-json-ref-03)
 - format (See [Data Type Formats](#dataTypeFormat) for further details)
 - title
-- description ([GFM syntax](https://help.github.com/articles/github-flavored-markdown) can be used for rich text representation)
+- description ([GFM syntax](https://guides.github.com/features/mastering-markdown/#GitHub-flavored-markdown) can be used for rich text representation)
 - default (Unlike JSON Schema, the value MUST conform to the defined type for the Schema Object)
 - multipleOf
 - maximum