The broadcast kitten

Fixes #1569

docs/changelog.rst

@@ -7,6 +7,9 @@ To update |kitty|, :doc:`follow the instructions <binary>`.
 0.19.3 [future]
 -------------------
 
+- A new :doc:`broadcast <kittens/broadcast>` kitten to type in all kitty windows
+  simultaneously (:iss:`1569`)
+
 - Add a new mappable `select_tab` action to choose a tab to switch to even
   when the tab bar is hidden (:iss:`3115`)
 

docs/kittens/broadcast.rst

@@ -0,0 +1,23 @@
+broadcast - type text in all kitty windows
+==================================================
+
+The ``broadcast`` kitten can be used to type text simultaneously in
+all kitty windows (or a subset as desired).
+
+To use it, simply create a mapping in :file:`kitty.conf` such as::
+
+    map F1 launch --allow-remote-control kitty +kitten broadcast
+
+Then press the :kbd:`F1` key and whatever you type in the newly created widow
+will be sent to all kitty windows.
+
+You can use the options described below to control which windows
+are selected.
+
+.. program:: kitty +kitten broadcast
+
+
+Command Line Interface
+--------------------------
+
+.. include:: /generated/cli-kitten-broadcast.rst

docs/remote-control.rst

@@ -148,6 +148,19 @@ as the syntax for what follows :code:`kitty @` above. You do not need
 to enable remote control to use these mappings.
 
 
+Broadcasting what you type to all kitty windows
+--------------------------------------------------
+
+As a simple illustration of the power of remote control, lets
+have what we type sent to all open kitty windows. To do that define the
+following mapping in :file:`kitty.conf`::
+
+    map F1 launch --allow-remote-control kitty +kitten broadcast
+
+Now press, F1 and start typing, what you type will be sent to all windows,
+live, as you type it.
+
+
 Documentation for the remote control protocol
 -----------------------------------------------