📝 Change default branch name

.github/CONTRIBUTING.md

@@ -20,11 +20,11 @@ chance of keeping on top of things.
 ## Making Changes
 
 - Create a topic branch from where you want to base your work.
-  - This is usually the master branch.
+  - This is usually the main branch.
   - Only target release branches if you are certain your fix must be on that
     branch.
-  - To quickly create a topic branch based on master; `git branch master/my_contribution master` then checkout the new branch with `git checkout master/my_contribution`. Better avoid working directly on the
-    `master` branch, to avoid conflicts if you pull in updates from origin.
+  - To quickly create a topic branch based on main; `git branch main/my_contribution main` then checkout the new branch with `git checkout main/my_contribution`. Better avoid working directly on the
+    `main` branch, to avoid conflicts if you pull in updates from origin.
 - Make commits of logical units.
 - Check for unnecessary whitespace with `git diff --check` before committing.
 - Use descriptive commit messages and reference the #issue number.