Move pages under tldr, lint run.sh, update docs

tldr/git-sync

@@ -0,0 +1,22 @@
+---
+syntax: markdown
+tags: [tldr, common]
+source: https://github.com/tldr-pages/tldr.git
+---
+# git sync
+
+> Sync local branches with remote branches.
+> Part of `git-extras`.
+> More information: <https://github.com/tj/git-extras/blob/master/Commands.md#git-sync>.
+
+- Sync the current local branch with its remote branch:
+
+`git sync`
+
+- Sync the current local branch with the remote main branch:
+
+`git sync origin main`
+
+- Sync without cleaning untracked files:
+
+`git sync -s {{remote_name}} {{branch_name}}`