Fixes: PR template updated to provide detailed instructions

.github/PULL_REQUEST_TEMPLATE/PR_TEMPLATE.md

@@ -1,25 +1,91 @@
-Description of PR...
+<!---
 
-## Changes
+Provide a short summary in the Title above. Examples of good PR titles:
+
+* "Feature: adds metrics to component"
+
+* "Fix: resolves duplication in comment thread"
+
+* "Update: apollo v2.34.0"
+
+-->
+
+## Description & motivation
+
+<!---
+
+Describe your changes, and why you're making them.  What benefit will this have to others?
+
+Is this linked to an open Github issue, a thread in Speckle community,
+or another pull request? Link it here.
+
+If it is related to a Github issue, and resolves it, please link to the issue number, e.g.:
+Fixes #85, Fixes #22, Fixes username/repo#123
+Connects #123
+
+-->
+
+## Changes:
+
+<!---
 
 - Item 1
 - Item 2
 
-## Checklist
+-->
 
-- [ ] Unit tests
-- [ ] Documentation
+## To-do before merge
 
-## References
+<!---
 
-(optional)
+(Optional -- remove this section if not needed)
 
-Include **important** links regarding the implementation of this PR.
-This usually includes and RFC or an aggregation of issues and/or individual conversations
-that helped put this solution together. This helps ensure there is a good aggregation
-of resources regarding the implementation.
+Include any notes about things that need to happen before this PR is merged, e.g.:
 
-```text
-Fixes #85, Fixes #22, Fixes username/repo#123
-Connects #123
-```
+- [ ] Change the base branch
+
+- [ ] Ensure PR #56 is merged
+
+-->
+
+## Screenshots:
+
+<!---
+
+Include a screenshot the before and after.  This can be a screenshot of a plugin, web frontend, or output in a terminal.
+
+-->
+
+## Validation of changes:
+
+<!---
+
+Describe what tests have been added or amended, and why these demonstrate it works and will prevent this feature being accidentally broken by future changes.
+
+-->
+
+## Checklist:
+
+<!---
+
+This checklist is mostly useful as a reminder of small things that can easily be
+
+forgotten – it is meant as a helpful tool rather than hoops to jump through.
+
+Put an `x` in all the items that apply, make notes next to any that haven't been
+
+addressed, and remove any items that are not relevant to this PR.
+
+-->
+
+- [ ] My pull request follows the guidelines in the Contributing document?
+
+- [ ] My pull request does not duplicate any other open [Pull Requests](../../../pulls) for the same update/change?
+
+- [ ] My commits are related to the pull request and do not amend unrelated code or documentation.
+
+- [ ] My code follows a similar style to existing code.
+
+- [ ] I have added appropriate tests.
+
+- [ ] I have updated or added relevant documentation.