TINY-11468: Updated everything to v7

[spocke]

A bunch of changes:

1. Added .editorconfig so that files are saved consistently using different editors
2. Added github templates
3. Added the new LicenseKey option
4. Switched the channels and docs from 6 to 7
5. Added the readme as a nuspec property should update the readme part of the nuget page
6. Removed .NET 5-7 support 8 is the officially supported version
7. Fixed various build warnings
8. Updated the build scripts so that they build, clean, and restore projects
9. Added a new example on how to load a local version of tinymce to test out the the LicenseKey property
10. Bumped the docker instance to use .NET 8
11. Fixed so both projects are built by CI
12. Removed the old .NET 5 js file and docs for that since we no longer support that
13. Bumped the version of the package to 2.0.0 since this is a breaking change