Invalid URLs fixes for OfficeDev Training content and Office Fabric UI (SharePoint#2016)

* Update sharepoint-add-ins-ux-design-guidelines.md

* Update search-api-usage-sharepoint-add-in.md

* Update Security.md

Author: ekapic

docs/scenario-guidance/Security.md

@@ -31,7 +31,7 @@ _**Applies to:** Office 365 | SharePoint Server_
 - [Important aspects of the SharePoint Add-in architecture and development landscape](https://docs.microsoft.com/en-us/sharepoint/dev/sp-add-ins/important-aspects-of-the-sharepoint-add-in-architecture-and-development-landscap)
 - [Authorize provider-hosted add-in users at run time by using OAuth](https://docs.microsoft.com/en-us/sharepoint/dev/solution-guidance/authorize-provider-hosted-add-in-users-at-run-time-by-using-oauth)
 - [Build mobile apps for other platforms using SharePoint](https://docs.microsoft.com/en-us/sharepoint/dev/general-development/build-mobile-apps-for-other-platforms-using-sharepoint)
-- [Moving Full Trust Code to the Cloud](https://github.com/OfficeDev/TrainingContent/tree/master/Archive/O3651/O3651-4%20Moving%20Full%20Trust%20Code%20to%20the%20cloud%20using%20repeatable%20patterns%20and%20best%20practices)
+- [Moving Full Trust Code to the Cloud](https://github.com/OfficeDev/TrainingContent/blob/master/SharePoint/AddIns/04%20Moving%20Full%20Trust%20Code%20to%20the%20cloud%20using%20repeatable%20patterns%20and%20best%20practices/Lab.md)
 - [A Series of Visual Studio Solutions to Accompany the MSDN Tutorial Series about Provider-hosted Add-ins](https://github.com/OfficeDev/SharePoint_Provider-hosted_Add-ins_Tutorials)
 
 ### Videos
@@ -109,4 +109,4 @@ When your Office 365 tenant is hosted in an specific environment like the German
 
 - [Authorization considerations for tenants hosted in the Germany, China or US Government environments](https://docs.microsoft.com/en-us/sharepoint/dev/solution-guidance/extending-sharepoint-online-for-germany-china-usgovernment-environments)
 - [Learn about Office 365 Germany](https://support.office.com/en-US/article/Learn-about-Office-365-Germany-8a5a4bbc-667a-4cac-8769-d8ac9015db4c)
-- [Learn about Office 365 operated by 21Vianet](https://support.office.com/en-us/article/Learn-about-Office-365-operated-by-21Vianet-A8AB5061-3346-4DA0-BB7C-5260822B53AE)
+- [Learn about Office 365 operated by 21Vianet](https://support.office.com/en-us/article/Learn-about-Office-365-operated-by-21Vianet-A8AB5061-3346-4DA0-BB7C-5260822B53AE)

docs/solution-guidance/search-api-usage-sharepoint-add-in.md

@@ -185,7 +185,7 @@ This API is a great fit for SharePoint-hosted Add-ins and Provider-hosted Add-in
 
 The following sample demonstrates how to execute searches with the SharePoint Search Service with the REST API from managed .Net code.
 
-- [EmployeeDirectory (OfficeDev Training Content)](https://github.com/OfficeDev/TrainingContent/blob/master/Archive/O3656/O3656-6%20Deep%20Dive%20into%20Search%20Scenarios%20in%20Office%20365/Demos/EmployeeDirectory)
+- [EmployeeDirectory (OfficeDev Training Content)](https://github.com/OfficeDev/TrainingContent/tree/master/SharePoint/Capabilities/02%20Deep%20Dive%20into%20Search%20Scenarios%20in%20Office%20365/Demos/EmployeeDirectory)
 
 The **Index** method in the [HomeController.cs class](https://github.com/OfficeDev/TrainingContent/blob/master/Archive/O3656/O3656-6%20Deep%20Dive%20into%20Search%20Scenarios%20in%20Office%20365/Demos/EmployeeDirectory/EmployeeDirectoryWeb/Controllers/HomeController.cs) executes a search for  all users whose last name begins with the text value the user clicks.
 

docs/sp-add-ins/sharepoint-add-ins-ux-design-guidelines.md

@@ -289,7 +289,7 @@ Just add the Office UI Fabric files to your development project, and include a r
 
 **5. How can Office UI Fabric Components be used in SharePoint Add-ins?**
 
-Just add a reference to the fabric.components.css library to your HTML or ASPX page. For details, see [Getting started](https://developer.microsoft.com/en-us/fabric#/get-started#core).
+Just add a reference to the fabric.components.css library to your HTML or ASPX page. For details, see [Getting started](https://github.com/OfficeDev/Office-UI-Fabric#get-started).
 
 **6. Can I use Office UI Fabric along with a SharePoint Add-in's host web CSS?**