This directory collects "newsfragments": short files that each contain a snippet of ReST-formatted text that will be added to the next release notes. This should be a description of aspects of the change (if any) that are relevant to users. (This contrasts with your commit message and PR description, which are a description of the change as relevant to people working on the code itself.)
Each file should be named like <ISSUE>.<TYPE>.rst, where
<ISSUE> is an issue numbers, and <TYPE> is one of:
featurebugfixdocremovalmisc
So for example: 123.feature.rst, 456.bugfix.rst
If your PR fixes an issue, use that number here. If there is no issue, then after you submit the PR and get the PR number you can add a newsfragment using that instead.
Note that the towncrier tool will automatically
reflow your text, so don't try to do any fancy formatting. You can
install towncrier and then run towncrier --draft if you want
to get a preview of how your change will look in the final release
notes.