Update cheatsheets

tldr/mkfifo

@@ -11,3 +11,11 @@ source: https://github.com/tldr-pages/tldr.git
 - Create a named pipe at a given path:
 
 `mkfifo {{path/to/pipe}}`
+
+- Send data through a named pipe and send the command to the background:
+
+`echo {{"Hello World"}} > {{path/to/pipe}} &`
+
+- Receive data through a named pipe:
+
+`cat {{path/to/pipe}}`