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

tldr/hg-update

@@ -0,0 +1,25 @@
+---
+syntax: markdown
+tags: [tldr, common]
+source: https://github.com/tldr-pages/tldr.git
+---
+# hg update
+
+> Update the working directory to a specified changeset.
+> More information: <https://www.mercurial-scm.org/doc/hg.1.html#update>.
+
+- Update to the tip of the current branch:
+
+`hg update`
+
+- Update to the specified revision:
+
+`hg update --rev {{revision}}`
+
+- Update and discard uncommitted changes:
+
+`hg update --clean`
+
+- Update to the last commit matching a specified date:
+
+`hg update --date {{dd-mm-yyyy}}`