docs: add WpConf documentation page

docs/rst/c_api.rst

@@ -34,6 +34,7 @@ C API Documentation
    c_api/plugin_api.rst
    c_api/component_loader_api.rst
    c_api/settings_api.rst
+   c_api/conf_api.rst
    c_api/session_item_api.rst
    c_api/si_interfaces_api.rst
    c_api/si_factory_api.rst

docs/rst/c_api/conf_api.rst

@@ -0,0 +1,16 @@
+.. _conf_api:
+
+Static Configuration
+====================
+.. graphviz::
+  :align: center
+
+   digraph inheritance {
+      rankdir=LR;
+      GObject -> WpConf;
+   }
+
+.. doxygenstruct:: WpConf
+
+.. doxygengroup:: wpconf
+   :content-only:

docs/rst/c_api/meson.build

@@ -2,6 +2,7 @@
 sphinx_files += files(
   'client_api.rst',
   'component_loader_api.rst',
+  'conf_api.rst',
   'core_api.rst',
   'device_api.rst',
   'global_proxy_api.rst',