New: Add type annotation to class properties (fixes #190)

[Pajn]

Type information is preserved for interface properties and object type literals, seems to just be missing on class properties.

[eslintbot]

Thanks for the pull request, @Pajn! I took a look to make sure it's ready for merging and found some changes are needed:

• Pull requests with code require an issue to be mentioned at the end of the commit summary, such as (fixes #1234). Please update the commit summary with an issue (file a new issue if one doesn't already exist).

Can you please update the pull request to address these?

(More information can be found in our pull request guide.)

[JamesHenry]

Hi, @Pajn! Thanks a lot for contributing (and starting the PR for more prettier work). I am excited about what that can become.

This LGTM, I think it should really be a Fix: commit, though. I will amend it whilst merging in this case.

[Pajn]

I think it should really be a Fix: commit, though. I will amend it whilst merging in this case.
Ah, sorry. Still learning your conventions :)

Your integration of this project into prettier made it easy to incrementally improve TS support so huge thanks for that!

[JamesHenry]

For sure! Let's make this happen 😄