SidePanel: add render prop with the open status

[sohkai]

See aragon/aragon-apps#717 (comment).

Nested components to the SidePanel will likely want to do different things based on whether or not it's opened.

[kushagrasharma]

Hi! I'm interested in working on this issue. Seems like a good place to start for someone new to the project.

Since I am new, what's the best way to get onboarded to contributing to Aragon UI/Aragon as a whole? I didn't see a contributors doc, are there best practices, tests, a chat, or anything else like that I should know about before diving in?

Thanks 😄

[bpierre]

Hi @kushagrasharma, that’s great! Yes it would be nice to have access to this information, let me know if you want to discuss anything before opening your first PR!

Since I am new, what's the best way to get onboarded to contributing to Aragon UI/Aragon as a whole? I didn't see a contributors doc, are there best practices, tests, a chat, or anything else like that I should know about before diving in?

The chat is generally a good place to start with, you could join the #dev and #dev-frontend channels on https://aragon.chat/ (I am @bpierre there too).

A proper contributor’s guide is coming to aragonUI, but in the meantime, you can check these two documents:

• https://github.com/aragon/aragon-apps/blob/master/CONTRIBUTING.md
• https://gist.github.com/bpierre/22572415b90577aa17e5953fa68980eb

Talk to you soon 🤗

[bpierre]

Done in https://github.com/aragon/aragon-ui/pull/616