adds pull request template

[bileschi]

DEV adds default pull request template to help remind contributors to use PR commit message tags.

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This change is 

[nsthorat]

Thanks for looking into this.

So the PR description isn't actually what matters, it's what we end up putting in the git commit message. Is there a way to set up the template for that instead?

[nsthorat]

And to be clear, the PR description doesn't automatically get added to the commit message.

[nsthorat]

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Review status: 0 of 1 files reviewed at latest revision, all discussions resolved, some commit checks failed.

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Comments from Reviewable

[caisq]

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Review status: 0 of 1 files reviewed at latest revision, all discussions resolved, some commit checks pending.

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Comments from Reviewable

[dsmilkov]

We still need to manually copy the PR desc into the commit message when we squash and merge right? or does this template show up in the squash-and-merge message as well?

[bileschi]

@dsmilkov The user still needs to write their own squash & merge commit message.

Unfortunately there does not seem to be a good way to automatically populate the commit message. It would require modifying the .git/config in a way that would not survive cloning the repo. We could hack something up, perhaps a script, which modifies the user's config, but that sounds pretty risky & ugly.

[nsthorat]

We still have to copy paste it, but this will at least help us remember.

[manrajgrover]

I feel we should move templates and contributing file to .github folder which seems to be a general convention.

[manrajgrover]

I was thinking if we can automate adding PR title as commit title and PR description as commit description. Turns out there is already a Chrome extension that does it. Sharing it here: https://github.com/sindresorhus/refined-github

[dsmilkov]

I installed the extension and works great for me (copies the PR title and description into the commit)!