docs: shuffle files to have the same logical hierarchy as on the generated doc

Also:
 - rename some files to remove redundant information from the filenames
 - rename many labels to match the filename and its place in the hierarchy
 - move lua_api under the scripting section

docs/rst/scripting/lua_api/lua_local_module_api.rst

@@ -0,0 +1,26 @@
+ .. _lua_local_module_api:
+
+Local Modules
+=============
+
+The `LocalModule` object (which binds the :c:struct:`WpImplModule` C API) provides a way
+to load PipeWire modules in the WirePlumber process. Instantiating the object
+loads the module, and when the last reference to the returned module object is
+dropped, the module is unloaded.
+
+Constructors
+~~~~~~~~~~~~
+
+.. function:: LocalModule(name, arguments, properties)
+
+   Loads the named module with the provided arguments and properties (either of
+   which can be ``nil``).
+
+   :param string name: the module name, such as ``"libpipewire-module-loopback"``
+   :param string arguments: should be either ``nil`` or a string with the desired
+        module arguments
+   :param table properties: can be ``nil`` or a table that can be
+        :ref:`converted <lua_gobject_lua_to_c>` to :c:struct:`WpProperties`
+   :returns: a new LocalModule
+   :rtype: LocalModule (:c:struct:`WpImplModule`)
+   :since: 0.4.2