Document the clipboard kitten

docs/index.rst

@@ -246,6 +246,10 @@ Some prominent kittens:
     Draw a GPU accelerated dock panel on your desktop showing the output
     from an arbitrary terminal program.
 
+:doc:`Clipboard <kittens/clipboard>`
+    Copy/paste to the clipboard from shell scripts, even over SSH.
+
+
 .. _sessions:
 
 Startup Sessions

docs/kittens/clipboard.rst

@@ -0,0 +1,27 @@
+clipboard - copy/paste to the system clipboard
+==================================================
+
+.. highlight:: sh
+
+
+The ``clipboard`` kitten can be used to read or write to the system clipboard
+from the shell. It even works over SSH. Using it is as simple as::
+
+    echo hooray | kitty +kitten clipboard
+
+All text received on :file:`stdin` is copied to the clipboard.
+
+To get text from the clipboard you have to enable reading of the clipboard
+in :opt:`clipboard_control` in :file:`kitty.conf`. Once you do that, you can
+use::
+
+    kitty +kitten clipboard --get-clipboard
+
+
+.. program:: kitty +kitten clipboard
+
+
+Command Line Interface
+--------------------------
+
+.. include:: /generated/cli-kitten-clipboard.rst