Update core web part tutorials for 1.14 new project templates (SharePoint#7715)

* Consolidate SPFx generator page

- consolidate existing Yeoman "scaffolding" page => new generator page
- moved SPFx generator page => tools & libraries
- updated links to point to the new file

* update wp tutorial to match spfx v1.14 experience

* update wp prop validation article

- modified images to focus on property pane

* update custom prop control article

- modified images to focus on property pane

* update "Use cascading dropdowns in web part properties" article

- modified images to focus on property pane

* Remove SPFx for Office Add-ins

- removed capability in SPFx v1.14
- removed articles & referenced images
- redirect URLs to 1.14 release notes

* fix automated feedback issues

* update guidance on latest GA version of SPFx

* update docs to match spfx v1.14 generator prompts

* address automated check feedback

Author: andrewconnell

.openpublishing.redirection.json

@@ -79,6 +79,21 @@
             "source_path": "docs/general-development/office-365-cdn.md",
             "redirect_url": "/office365/enterprise/use-office-365-cdn-with-spo",
             "redirect_document_id": false
+        },
+        {
+            "source_path": "docs/spfx/toolchain/scaffolding-projects-using-yeoman-sharepoint-generator.md",
+            "redirect_url": "docs/spfx/yeoman-generator-for-spfx-intro.md",
+            "redirect_document_id": false
+        },
+        {
+            "source_path": "docs/spfx/office-addins-create.md",
+            "redirect_url": "docs/spfx/release-1.14.md",
+            "redirect_document_id": false
+        },
+        {
+            "source_path": "docs/spfx/web-parts/get-started/office-addins-tutorial.md",
+            "redirect_url": "docs/spfx/release-1.14.md",
+            "redirect_document_id": false
         }
     ]
-}
+}