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

tldr/xgettext

@@ -0,0 +1,25 @@
+---
+syntax: markdown
+tags: [tldr, common]
+source: https://github.com/tldr-pages/tldr.git
+---
+# xgettext
+
+> Extract gettext strings from code files.
+> More information: <https://www.gnu.org/software/gettext/manual/html_node/xgettext-Invocation.html>.
+
+- Scan file and output strings to `messages.po`:
+
+`xgettext {{path/to/input_file}}`
+
+- Use a different output filename:
+
+`xgettext --output {{path/to/output_file}} {{path/to/input_file}}`
+
+- Append new strings to an existing file:
+
+`xgettext --join-existing --output {{path/to/output_file}} {{path/to/input_file}}`
+
+- Don't add a header containing metadata to the output file:
+
+`xgettext --omit-header {{path/to/input_file}}`