Add Flow types to website source

[bvaughn]

Replace PropTypes with Flow types for our components in www (and make sure yarn flow checks these types to protect against regressions).

I got the ball rolling with commit 1de4c66

This Twitter thread also has some interesting discussion for auto-generating Flow types for Gatsby's graphql queries.

[hd719]

Hey sorry @bvaughn is this now closed?
Actually never mind, I looked at it wrong, the issue #10897 is closed. Sorry about that

[bvaughn]

No problem. 😄 Are you interested in helping out with this issue? Lots of work to be done here. Could be cool!

[hd719]

Hey @bvaughn yes I am still kind of new to open source and still learning Flow Types, but yes I would like to help out on this particular issue.

[bvaughn]

Okay! Great.

This is a pretty big issue, so my advice is- let's do it a couple files at a time. That way it's easier to review and we don't risk conflicting with every other PR.

[hd719]

Sounds good!

[tricinel]

I can help as well. Going through a couple of files at a time seems like a good idea.

[bvaughn]

Okay. I'll mark this issue in-progress.

Communicate here to avoid stepping on each other's toes. 😄

[tricinel]

Awesome. I've already opened a PR for it (but forgot to mention the issue number on the commit): #156. Sorry about that. Perhaps if it checks out, then it can be merged so that we keep on top of it and avoid conflicts as much as possible?

I'd like to continue working on it though. So I can continue on it next week if that's ok. I'll work through the src/components files first.

Do you think it's worth doing the utils as well? Adding flow typechecking there as well?

[bvaughn]

Do you think it's worth doing the utils as well? Adding flow typechecking there as well?

Yeah 😄