Bump version

Bump copyright year
Update xUnit

Add the finishing touch to 7.0

- Target .NET 6.0
- Enable source link
- Add templates to README
- Bump copyright year
- Link to T4 issue preventing VB in templates
- Update .gitignore

Update to EF Core 6.0 GA

Fixes #62

Initialize skip collection navigations

Fix keyColumnType was not generated for DeleteDataOperations during m…

…igration.

+ Other minor fixes.

Fix scaffolding modelBuilder annotations (#35)

Clean up