doc: Undocument internal client `urgent` and `shape` methods.

There is already some permissions to change the behavior. I don't
think there is valid user-facing use cases for these "methods".

docs/config.ld

@@ -517,6 +517,7 @@ file = {
         -- exclude these modules, as they do not contain any written
         -- documentation
         '../lib/awful/autofocus.lua',
+        '../lib/awful/client/shape.lua',
         '../lib/awful/dbus.lua',
         '../lib/awful/_compat.lua',
         '../lib/awful/init.lua',
@@ -525,6 +526,7 @@ file = {
         '../lib/awful/startup_notification.lua',
         '../lib/awful/mouse/drag_to_tag.lua',
         '../lib/awful/permissions/_common.lua',
+        '../lib/awful/client/urgent.lua',
         '../lib/gears/init.lua',
         '../lib/wibox/layout/init.lua',
         '../lib/wibox/container/init.lua',

lib/awful/client/urgent.lua

@@ -26,7 +26,7 @@ end
 
 local data = setmetatable({}, { __mode = 'k' })
 
---- Get the first client that got the urgent hint.
+-- Get the first client that got the urgent hint.
 --
 -- @function awful.urgent.get
 -- @treturn client.object The first urgent client.
@@ -57,7 +57,7 @@ function urgent.jumpto(merge)
     end
 end
 
---- Adds client to urgent stack.
+-- Adds client to urgent stack.
 --
 -- @function awful.urgent.add
 -- @tparam client c The client object.
@@ -88,7 +88,7 @@ function urgent.add(c, prop)
     end
 end
 
---- Remove client from urgent stack.
+-- Remove client from urgent stack.
 --
 -- @function awful.urgent.delete
 -- @tparam client c The client object.