git-delete-branch: add page (#6011)

pages/common/git-delete-branch.md

@@ -0,0 +1,13 @@
+# git delete-branch
+
+> Delete local and remote Git branches.
+> Part of `git-extras`. If deleting the checked out branch, only the remote branch will be deleted.
+> More information: <https://github.com/tj/git-extras/blob/master/Commands.md#git-delete-branch>.
+
+- Delete a local and remote Git branch:
+
+`git delete-branch {{branch_name}}`
+
+- Delete multiple local and remote Git branches:
+
+`git delete-branch {{branch_name1 branch_name2 ...}}`