Update contributing guidelines with style suggestions for pull requests

[KirstieJane]

I've noticed that the PRs for tedana often have labels like [WIP], [TST], [ENH] associated with them.

I think it makes sense to explain in the contributing guidelines what they mean and how to use them for new pull requests.

You could also consider a pull request template. @Islast has a really lovely one for Brain Networks in Python.

Here's a github help article about pull request templates.

[emdupre]

Yes, PR label conventions would be something to include in more general style guidelines ! I'm planning to add those— maybe in the documentation itself, with a link out from the Contributing file. Something like these suggested tags from Nibabel.

I love the idea of a pull request template too, though ! Would be great to have help in creating one for this repo.

[KirstieJane]

My favourite thing about @Islast's template is the checkbox that tells me whether it's ready for review. I get the notifications when she pushes commits but I know not to go and check it out until that checkbox is ✅!

Isla's on holiday at the moment but I'm sure she'd be delighted to help out when she's back in about 1 week (or other folks could share their experiences too) ✨

[Islast]

Hi, just saw this in my notifications and I thought I'd say hi! I think pull request templates are great. One tip I have if you decide to do one is that if you look at the raw file of ours you'll see a section in a ! html tag:

<!---
This is a suggested pull request template for the BrainNetworksInPython. 
We don't mind whether or not you use it. It's just a list of useful 
questions to answer. :)
-->

Github markdown doesn't render anything enclosed in this tag so it's useful for leaving an explanatory message to your pull-requester 💫