feat(PULL_REQUEST_TEMPLATE): simpler and easier to use

Co-authored-by: Pierre Donias <pierre.donias@gmail.com>

PULL_REQUEST_TEMPLATE.md

@@ -1,28 +1,16 @@
-### Check list
+### Description
 
-> Check if done, if not relevant leave unchecked.
+_Short explanation of this PR (feel free to re-use commit message)_
 
-- [ ] PR reference the relevant issue (e.g. `Fixes #007` or `See xoa-support#42`)
-- [ ] if UI changes, a screenshot has been added to the PR
-- [ ] documentation updated
-- `CHANGELOG.unreleased.md`:
-  - [ ] enhancement/bug fix entry added
-  - [ ] list of packages to release updated (`${name} v${new version}`)
-- **I have tested added/updated features** (and impacted code)
-  - [ ] unit tests (e.g. [`cron/parse.spec.js`](https://github.com/vatesfr/xen-orchestra/blob/b24400b21de1ebafa1099c56bac1de5c988d9202/%40xen-orchestra/cron/src/parse.spec.js))
-  - [ ] if `xo-server` API changes, the corresponding test has been added to/updated on [`xo-server-test`](https://github.com/vatesfr/xen-orchestra/tree/master/packages/xo-server-test)
-  - [ ] at least manual testing
+### Checklist
 
-### Process
-
-1. create a PR as soon as possible
-1. mark it as `WiP:` (Work in Progress) if not ready to be merged
-1. when you want a review, add a reviewer (and only one)
-1. if necessary, update your PR, and re- add a reviewer
-
-From [_the Four Agreements_](https://en.wikipedia.org/wiki/Don_Miguel_Ruiz#The_Four_Agreements):
-
-1. Be impeccable with your word.
-1. Don't take anything personally.
-1. Don't make assumptions.
-1. Always do your best.
+- Commit
+  - Title follows [commit conventions](https://bit.ly/commit-conventions)
+  - Reference the relevant issue (`Fixes #007`, `See xoa-support#42`, `See https://...`)
+  - If bug fix, add `Introduced by`
+- Changelog
+  - If visible by XOA users, add changelog entry
+  - Update "Packages to release" in `CHANGELOG.unreleased.md`
+- PR
+  - If UI changes, add screenshots
+  - If not finished or not tested, open as _Draft_