Update compatibility.md

removed support for Node V12 for SPFx 1.15.0 releases and above

Author: lucabandMSFT

docs/spfx/compatibility.md

@@ -33,8 +33,8 @@ The following table lists SharePoint Framework and compatible versions of common
 
 |              SPFx               |   Node.js (LTS) |                    NPM                    |   TypeScript   |    React    |
 | ------------------------------- | --------------- | ----------------------------------------- | -------------- | ----------- |
-| [1.15.2](release-1.15.2.md)     | v12,  v14,  v16 | v5, v6, v7, v8                            | v4.5           | v16.13.1    |
-| [1.15.0](release-1.15.md)       | v12,  v14,  v16 | v5, v6, v7, v8                            | v4.5           | v16.13.1    |
+| [1.15.2](release-1.15.2.md)     | v14,  v16       | v5, v6, v7, v8                            | v4.5           | v16.13.1    |
+| [1.15.0](release-1.15.md)       | v14,  v16       | v5, v6, v7, v8                            | v4.5           | v16.13.1    |
 | [1.14.0](release-1.14.md)       | v12,  v14       | v5, v6                                    | v3.9           | v16.13.1    |
 | [1.13.1](release-1.13.1.md)     | v12,  v14       | v5, v6                                    | v3.9           | v16.13.1    |
 | [1.13.0](release-1.13.md)       | v12,  v14       | v5, v6                                    | v3.9           | v16.13.1    |