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

tldr/true

@@ -0,0 +1,14 @@
+---
+syntax: markdown
+tags: [tldr, common]
+source: https://github.com/tldr-pages/tldr.git
+---
+# true
+
+> Returns a successful exit status code of 0.
+> Use this with the || operator to make a command always exit with 0.
+> More information: <https://www.gnu.org/software/coreutils/true>.
+
+- Return a successful exit code:
+
+`true`