Change the “master” Branch in Git to “trunk”

git checkout -b trunk master # Create and switch to the
                             # trunk branch
git push -u origin trunk     # Push the trunk branch to
                             # the remote and track it
git branch -d master         # Delete local master
#
# Log into Bitbucket, go to the "Repository settings",
# and change the "Main branch" from "master" to "trunk".
#
git push --delete origin master # Delete remote master
git remote prune origin         # Delete the remote
                                # tracking branch