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

tldr/linux/tac

@@ -0,0 +1,30 @@
+---
+syntax: markdown
+tags: [tldr, linux]
+source: https://github.com/tldr-pages/tldr.git
+---
+# tac
+
+> Display and concatenate files with lines in reversed order.
+> See also: `cat`.
+> More information: <https://www.gnu.org/software/coreutils/tac>.
+
+- Concatenate specific files in reversed order:
+
+`tac {{path/to/file1 path/to/file2 ...}}`
+
+- Display `stdin` in reversed order:
+
+`{{cat path/to/file}} | tac`
+
+- Use a specific separator:
+
+`tac --separator {{,}} {{path/to/file1 path/to/file2 ...}}`
+
+- Use a specific regex as a separator:
+
+`tac --regex --separator {{[,;]}} {{path/to/file1 path/to/file2 ...}}`
+
+- Use a separator before each file:
+
+`tac --before {{path/to/file1 path/to/file2 ...}}`