A new theme for the kitty website

Supports dark mode. Also re-organize the documentation
a bit, making it more hierarchical.

Have a nicer landing page

docs/clipboard.rst

@@ -0,0 +1,29 @@
+Pasting to clipboard
+=======================
+
+|kitty| implements the OSC 52 escape code protocol to get/set the clipboard
+contents (controlled via the :opt:`clipboard_control` setting). There is one
+difference in kitty's implementation compared to some other terminal emulators.
+|kitty| allows sending arbitrary amounts of text to the clipboard. It does so
+by modifying the protocol slightly. Successive OSC 52 escape codes to set the
+clipboard will concatenate, so::
+
+    <ESC>]52;c;<payload1><ESC>\
+    <ESC>]52;c;<payload2><ESC>\
+
+will result in the clipboard having the contents ``payload1 + payload2``. To
+send a new string to the clipboard send an OSC 52 sequence with an invalid payload
+first, for example::
+
+    <ESC>]52;c;!<ESC>\
+
+Here ``!`` is not valid base64 encoded text, so it clears the clipboard.
+Further, since it is invalid, it should be ignored by terminal emulators
+that do not support this extension, thereby making it safe to use, simply
+always send it before starting a new OSC 52 paste, even if you aren't chunking
+up large pastes, that way kitty won't concatenate your paste, and it will have
+no ill-effects in other terminal emulators.
+
+In case you're using software that can't be easily adapted to this
+protocol extension, it can be disabled by specifying ``no-append`` to the
+:opt:`clipboard_control` setting.