Update cheatsheets

rev

@@ -0,0 +1,17 @@
+---
+syntax: markdown
+tags: [tldr, common]
+source: https://github.com/tldr-pages/tldr.git
+---
+# rev
+
+> Reverse a line of text.
+> More information: <https://manned.org/rev>.
+
+- Reverse the text string "hello":
+
+`echo "hello" | rev`
+
+- Reverse an entire file and print to `stdout`:
+
+`rev {{path/to/file}}`