BREAKING CHANGE: The library now requires Angular v14

Closes #164

PR Checklist

Please check if your PR fulfills the following requirements:

• [x ] The commit message follows our guidelines: https://github.com/ngneat/reactive-forms/blob/master/CONTRIBUTING.md#commit
• [ x] Tests for the changes have been added (for bug fixes / features)
• [x ] Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

[ ] Bugfix
[x] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[ ] Documentation content changes
[ ] Other... Please describe:

What is the current behavior?

Issue Number: 164

What is the new behavior?

Basic compatibility with Angular 14. I've tried to also update nx, but ran into issues with tests.

Does this PR introduce a breaking change?

[x] Yes
[ ] No

Other information