Update contributing guide and PR template

.github/PULL_REQUEST_TEMPLATE.md

@@ -11,7 +11,9 @@ Remove this section if not relevant
 
 ### Merge requirements satisfied?
 **[NOTICE] Bug fixes or features added to Salt require tests.**
-<!-- Please review the [test documentation](https://docs.saltproject.io/en/master/topics/tutorials/writing_tests.html) for details on how to implement tests into Salt's test suite. -->
+<!-- Please review the test documentation for details on how to implement tests
+into Salt's test suite:
+https://docs.saltproject.io/en/master/topics/tutorials/writing_tests.html -->
 - [ ] Docs
 - [ ] Changelog - https://docs.saltproject.io/en/master/topics/development/changelog.html
 - [ ] Tests written/updated
@@ -19,7 +21,13 @@ Remove this section if not relevant
 ### Commits signed with GPG?
 Yes/No
 
-Please review [Salt's Contributing Guide](https://docs.saltproject.io/en/master/topics/development/contributing.html) for best practices, including the
+<!-- Please review Salt's Contributing Guide for best practices and guidance in
-[PR Guidelines](https://docs.saltproject.io/en/master/topics/development/pull_requests.html).
+choosing the right branch:
+https://docs.saltproject.io/en/master/topics/development/contributing.html -->
 
-See GitHub's [page on GPG signing](https://help.github.com/articles/signing-commits-using-gpg/) for more information about signing commits with GPG.
+<!-- Additional guidance for pull requests can be found here:
+https://docs.saltproject.io/en/master/topics/development/pull_requests.html -->
+
+<!-- See GitHub's page on GPG signing for more information about signing commits
+with GPG:
+https://help.github.com/articles/signing-commits-using-gpg/ -->

CONTRIBUTING.rst

@@ -1,30 +1,56 @@
-============
+==============================================
-Contributing
+Contributing to Salt: A Guide for Contributors
-============
+==============================================
 
-So you want to contribute to the Salt project? Excellent! You can help
+So, you want to contribute to the Salt project? That's fantastic! There are many
-in a number of ways:
+ways you can help improve Salt:
 
--  Use Salt and open well-written bug reports.
+- Use Salt and report bugs with clear, detailed descriptions.
--  Join a `working group <https://github.com/saltstack/community>`__.
+- Join a `working group <https://github.com/saltstack/community>`__ to
--  Answer questions on `irc <https://web.libera.chat/#salt>`__,
+  collaborate with other contributors.
-   the `community Discord <https://discord.com/invite/J7b7EscrAs>`__,
+- Answer questions on platforms like `IRC <https://web.libera.chat/#salt>`__,
-   the `salt-users mailing
+  the `community Discord <https://discord.com/invite/J7b7EscrAs>`__,
-   list <https://groups.google.com/forum/#!forum/salt-users>`__,
+  the `salt-users mailing list <https://groups.google.com/forum/#!forum/salt-users>`__,
-   `Server Fault <https://serverfault.com/questions/tagged/saltstack>`__,
+  `Server Fault <https://serverfault.com/questions/tagged/saltstack>`__,
-   or `r/saltstack on Reddit <https://www.reddit.com/r/saltstack/>`__.
+  or `r/saltstack on Reddit <https://www.reddit.com/r/saltstack/>`__.
--  Fix bugs.
+- Fix bugs or contribute to the `documentation <https://saltstack.gitlab.io/open/docs/docs-hub/topics/contributing.html>`__.
--  `Improve the documentation <https://saltstack.gitlab.io/open/docs/docs-hub/topics/contributing.html>`__.
+- Submit workarounds, patches, or code (even without tests).
-- Provide workarounds, patches, or other code without tests.
+- Share your experiences and solutions to problems you've solved using Salt.
-- Tell other people about problems you solved using Salt.
 
-If you'd like to update docs or fix an issue, you're going to need the
+Choosing the Right Branch for Your Pull Request
-Salt repo. The best way to contribute is using
+===============================================
-`Git <https://git-scm.com/>`__.
 
+We appreciate your contributions to the project! To ensure a smooth and
+efficient workflow, please follow these guidelines when submitting a Pull
+Request. Each type of contribution—whether it's fixing a bug, adding a feature,
+updating documentation, or fixing tests—should be targeted at the appropriate
+branch. This helps us manage changes effectively and maintain stability across
+versions.
+
+- **Bug Fixes:**
+
+  Create your Pull Request against the oldest supported branch where the bug
+  exists. This ensures that the fix can be applied to all relevant versions.
+
+- **New Features**:
+
+  For new features or enhancements, create your Pull Request against the master
+  branch.
+
+- **Documentation Updates:**
+
+  Documentation changes should be made against the master branch, unless they
+  are related to a bug fix, in which case they should follow the same branch as
+  the bug fix.
+
+- **Test Fixes:**
+
+  Pull Requests that fix broken or failing tests should be created against the
+  oldest supported branch where the issue occurs.
+
+Setting Up Your Salt Development Environment
+============================================
 
-Environment setup
-=================
 To hack on Salt or the docs you're going to need to set up your
 development environment. If you already have a workflow that you're
 comfortable with, you can use that, but otherwise this is an opinionated

doc/topics/development/pull_requests.rst

@@ -193,12 +193,21 @@ By default, PRs run a limited subset of the test suite against the following
 operating systems:
 
 * Linux:
+    - Latest ``Amazon Linux Arm64``
+    - Latest ``Amazon Linux x86_64``
+    - Latest ``Debian Linux Arm64``
+    - Latest ``Debian Linux x86_64``
+    - Latest ``Photon OS Arm64``
+    - Latest ``Photon OS x86_64``
+    - Latest ``Rocky Linux Arm64``
     - Latest ``Rocky Linux x86_64``
-    - Latest ``Amazon Linux aarch64``
+    - Latest ``Ubuntu LTS Arm64``
-    - Latest ``Ubuntu LTS arm64``
+    - Latest ``Ubuntu LTS x86_64``
-    - Latest ``Arch Linux x86_64``
+* Windows Server:
-* Latest ``Windows Server x86_64``
+    - Latest ``Windows Server x86_64``
-* Latest ``MacOS arm64``
+* macOS:
+    - Latest ``MacOS Arm64``
+    - Latest ``MacOS x86_64``
 
 Optional OS additions
 ---------------------