git-local-commits: add page (#5981)

pages/common/git-local-commits.md

@@ -0,0 +1,9 @@
+# git local-commits
+
+> Show local commits that haven't been pushed to origin. Any additional arguments will be passed directly to `git log`.
+> Part of `git-extras.
+> More information: <https://github.com/tj/git-extras/blob/master/Commands.md#git-local-commits>.
+
+- Show commits that haven't been pushed:
+
+`git local-commits`