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

tldr/diffstat

@@ -0,0 +1,17 @@
+---
+syntax: markdown
+tags: [tldr, common]
+source: https://github.com/tldr-pages/tldr.git
+---
+# diffstat
+
+> Create a histogram from the output of the `diff` command.
+> More information: <https://manned.org/diffstat>.
+
+- Display changes in a histogram:
+
+`diff {{path/to/file1}} {{path/to/file2}} | diffstat`
+
+- Display inserted, deleted and modified changes as a table:
+
+`diff {{path/to/file1}} {{path/to/file2}} | diffstat -t`