message: docs: Lua support is no longer experimental
  As of Lua support is no longer experimental.
diff: Scripting
  =========
  -Envoy supports experimental `Lua <https://www.lua.org/>`_ scripting as part of a dedicated
  +Envoy supports `Lua <https://www.lua.org/>`_ scripting as part of a dedicated
  :ref:`HTTP filter <config_http_filters_lua>`.
  