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

tldr/unexpand

@@ -0,0 +1,29 @@
+---
+syntax: markdown
+tags: [tldr, common]
+source: https://github.com/tldr-pages/tldr.git
+---
+# unexpand
+
+> Convert spaces to tabs.
+> More information: <https://www.gnu.org/software/coreutils/unexpand>.
+
+- Convert blanks in each file to tabs, writing to `stdout`:
+
+`unexpand {{path/to/file}}`
+
+- Convert blanks to tabs, reading from `stdout`:
+
+`unexpand`
+
+- Convert all blanks, instead of just initial blanks:
+
+`unexpand -a {{path/to/file}}`
+
+- Convert only leading sequences of blanks (overrides -a):
+
+`unexpand --first-only {{path/to/file}}`
+
+- Have tabs a certain number of characters apart, not 8 (enables -a):
+
+`unexpand -t {{number}} {{path/to/file}}`