add screen commands

docs/screen.rst

@@ -0,0 +1,16 @@
+screen
+========
+`screen <https://www.gnu.org/software/screen/manual/screen.html>`_ is a full-screen window manager that multiplexes a physical terminal between several processes, typically interactive shells.
+
+List available screens
+--------
+:code:`$ screen -ls`
+
+Start a new screen with name
+--------
+:code:`$ screen -S <screen_name>`
+
+Attach to session
+--------
+:code:`$ screen -R <screen_name>`
+