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

tldr/git-gc

@@ -0,0 +1,29 @@
+---
+syntax: markdown
+tags: [tldr, common]
+source: https://github.com/tldr-pages/tldr.git
+---
+# git gc
+
+> Optimise the local repository by cleaning unnecessary files.
+> More information: <https://git-scm.com/docs/git-gc>.
+
+- Optimise the repository:
+
+`git gc`
+
+- Aggressively optimise, takes more time:
+
+`git gc --aggressive`
+
+- Do not prune loose objects (prunes by default):
+
+`git gc --no-prune`
+
+- Suppress all output:
+
+`git gc --quiet`
+
+- Display help:
+
+`git gc --help`