docs: add Angular-Slickgrid 7.0 to compatibility table

Author: ghiscoding

README.md

@@ -62,6 +62,7 @@ For common issues, see the [Troubleshooting Section](#troubleshooting-section) b
 
 | Angular-Slickgrid | Angular version | Migration Guide | Notes |
 |-------------------|-----------------------|-----------------|------|
+| 7.x               | >=17.0               | [Migration 7.x](https://ghiscoding.gitbook.io/angular-slickgrid/migrations/migration-to-7.x)     | merge SlickGrid into Slickgrid-Universal, requires Slickgrid-Universal [4.x](https://github.com/ghiscoding/slickgrid-universal/releases/tag/v4.0.2) version |
 | 6.x               | >=16.0               | [Migration 6.x](https://github.com/ghiscoding/Angular-Slickgrid/wiki/Migration-to-6.x)     | removal of jQuery (now uses browser native code), requires Slickgrid-Universal [3.x](https://github.com/ghiscoding/slickgrid-universal/releases/tag/v3.0.0) version |
 | 5.x               | >=14.0               | [Migration 5.x](https://github.com/ghiscoding/Angular-Slickgrid/wiki/Migration-to-5.x)     | removal of jQueryUI, requires Slickgrid-Universal [2.x](https://github.com/ghiscoding/slickgrid-universal/releases/tag/v2.0.0) version |
 | 4.x               | >=13.0               | [Migration 4.x](https://github.com/ghiscoding/Angular-Slickgrid/wiki/Migration-to-4.x)     | for Ivy build only, requires Slickgrid-Universal [1.x](https://github.com/ghiscoding/slickgrid-universal/releases/tag/v1.1.1) version |