docs: clarify main/master branch (#390)

Author: RobPasMue

.github/pull_request_template.md

@@ -1,2 +1,8 @@
 > [!CAUTION]
 > **Do not commit any proprietary information belonging either to Ansys or to external sources. If you are uncertain, consult your manager.**
+
+> [!IMPORTANT]  
+> This repository used to have as its default branch ``master``. In order to align with the ecosystem
+> standards, the default branch's name has been changed for ``main``. The previous ``master`` branch is
+> left for avoiding breaking changes on our libraries, and it is being kept in sync with ``main``. Make sure
+> that any PR opened is targeting ``main``.

README.md

@@ -5,6 +5,12 @@
 This repository contains example datasets for PyAnsys projects.
 Examples contain non-confidential and non-proprietary data.
 
+> [!IMPORTANT]  
+> This repository used to have as its default branch ``master``. In order to align with the ecosystem
+> standards, the default branch's name has been changed for ``main``. The previous ``master`` branch is
+> left for avoiding breaking changes on our libraries, and it is being kept in sync with ``main``. Make sure
+> that any PR opened is targeting ``main``.
+
 ## Contributing
 
 To contribute to this repo, please read the [PyAnsys Contributing guide](https://dev.docs.pyansys.com/how-to/contributing.html).