Update PR template (#3153)

* Update PR template

---------

Co-authored-by: David A. Ham <david.ham@imperial.ac.uk>

.github/pull_request_template.md

@@ -1,61 +1,15 @@
----
-name: "Bug fix or new feature"
-description: ''
-title: ''
-labels: ''
-assignees: ''
-
----
-
 # Description
-Please include a summary of the changes introduced by this PR.
-Additionally include any relevant motivation and context. List any
-dependencies that are required for this change, other PRs upon
-which this may depend, and associated issues.
-
-## Associated Pull Requests:
-- Make a list (with links!)
-- [Like this PR#691](https://github.com/OP2/PyOP2/pull/691)
-
-## Fixes Issues:
-- Make a list of issues (with links!)
-- [Like this Issue#2824](https://github.com/firedrakeproject/firedrake/issues/2824)
-
-If issues are fixed by this PR, prepend each of them with the word
-"fixes", so they are automatically closed when this PR is merged. For
-example "fixes #123, fixes #456".
 
-# Checklist for author:
 
 <!--
-If you think an option is not relevant to your PR, do not delete it but use ~strikethrough formating on it~. This helps keeping track of the entire list.
--->
-
-- [ ] I have linted the codebase (`make lint` in the `firedrake` source directory).
-- [ ] My changes generate no new warnings.
-- [ ] All of my functions and classes have appropriate docstrings.
-- [ ] I have commented my code where its purpose may be unclear.
-- [ ] I have included and updated any relevant documentation.
-- [ ] Documentation builds locally (`make linkcheck; make html; make latexpdf` in `firedrake/docs` directory)
-- [ ] I have added tests specific to the issues fixed in this PR.
-- [ ] I have added tests that exercise the new functionality I have introduced
-- [ ] Tests pass locally (`pytest tests` in the `firedrake` source directory) (useful, but not essential if you don't have suitable hardware).
-- [ ] I have performed a self-review of my own code using the below guidelines.
-
-# Checklist for reviewer:
+Please include a summary of the changes introduced by this PR.
+Additionally be sure to link associated pull requests in other projects.
 
-- [ ] Docstrings present
-- [ ] New tests present
-- [ ] Code correctly commented
-- [ ] No bad "code smells"
-- [ ] No issues in parallel
-- [ ] No CI issues (excessive parallelism/memory usage/time/warnings generated)
-- [ ] Upstream/dependent branches and PRs are ready
+If issues are fixed by this PR, include link to them and prepend each of them with the word "fixes", so they are automatically closed when this PR is merged.
+For example "fixes #xyz, fixes #abc".
 
 Feel free to add reviewers if you know there is someone who is already aware of this work.
-
 Please open this PR initially as a draft and mark as ready for review once CI tests are passing.
 
-<!--
 Thanks for contributing!
 -->