Port to MathComp 2

.github/pull_request_template.md

@@ -8,12 +8,16 @@
 
 <!-- please fill in the following checklist -->
 - [ ] added corresponding entries in `CHANGELOG_UNRELEASED.md`
-  (do not edit former entries, only append new ones, be careful:
-   merge and rebase have a tendency to mess up `CHANGELOG_UNRELEASED.md`)
+
+<!-- only append to minimize problems when merging/rebasing -->
+<!-- consider the use of `changelog/changes.sh` from
+     https://github.com/math-comp/tools to generate the changelog -->
+
 - [ ] added corresponding documentation in the headers
+
 <!-- Cross-out the above items using ~crossed out item~ if they happen not to be relevant -->
 
 <!-- leave this note as a reminder to reviewers -->
 ##### Automatic note to reviewers
 
-Read [this Checklist](https://github.com/math-comp/math-comp/wiki/Checklist-for-following,-reviewing-and-playing-with-a-PR#checklist-for-reviewing-a-pr) and put a milestone if possible.
+Read [this Checklist](https://github.com/math-comp/math-comp/wiki/Checklist-for-creating-and-review-PRs) and put a milestone if possible.