- Note that Homebrew Cask issues should be filed elsewhere.
- Make `brew`/homebrew-core issue differential in simpler language
- Tell people to fix all `brew doctor` issues
- Refer to the issue checklist and make it even more clear and prominent
that we may close it out immediately if they don't use it.
Fixes https://github.com/Homebrew/brew/issues/2608
* ISSUE_TEMPLATE: tweak instructions.
Be clearer about what's expected and where to file things.
* ISSUE_TEMPLATE: tweak new formula title.
* ISSUE_TEMPLATE: formula not formulae
