add pull request template asking for relevant tracking issues
As mentioned at RustNation, I would like to remind PR authors to link to relevant tracking issues when opening PRs as it is otherwise very easy to forget doing so.
There's a certain amount of conflict between making the template as small as possible while still being clear for new contributors. I am very much open to changes here but really want to try this out.
Also unsure how much formal buy-in we need here. Maybe merge this pinging t-compiler and t-libs, and then ask how people feel about this on zulip in a few weeks?
r? `@davidtwco`
7a90db7fb1