Only annotate lines that the PR modifies

[Floby]

This PR adds the option annotations = 'changed-coverage'
When active, the action will filter any coverage annotations to only include lines that the PR actually modifies.
This is useful when inheriting a poorly covered codebase, but trying not to worsen the coverage, because otherwise annotations are ignored after the 50th.

See it in action at https://github.com/Floby/test-coverage-action/pull/1/files#diff-a2a171449d862fe29692ce031981047d7ab755ae7f84c707aef80701b3ea0c80

[ArtiomTr]

Hello @Floby 👋,

Thank you for this amazing PR! Just have a few notes on this.

[Floby]

There seems to be an issue with the package lock file as well. What would you like me to do with it?

[ArtiomTr]

Perfect 👍

[ArtiomTr]

@Floby, the package-lock file looks good to me, what is the issue? Also, it seems like the run.test.ts test is failing, can you please check and update it if necessary?

[HarelM]

Any way for me to help push this forward?
I would really love to see coverage annotation in our project so that I can direct PR writers to improve the coverage of the code they want to add to our library...

[ArtiomTr]

Thank you for contribution!

@all-contributors please add @Floby for code

[allcontributors]

@ArtiomTr

I've put up a pull request to add @Floby! 🎉

[Floby]

hello, sorry i've been on holiday and trying to detox ^^
Thank you for merging this !