doc: add brief explanations for all groups

spa/include/spa/support/cpu.h

@@ -35,7 +35,7 @@ extern "C" {
 #include <spa/utils/hook.h>
 
 /** \defgroup spa_cpu CPU
- *
+ * Querying CPU properties
  */
 
 /**

spa/include/spa/support/dbus.h

@@ -32,7 +32,7 @@ extern "C" {
 #include <spa/support/loop.h>
 
 /** \defgroup spa_dbus DBus
- *
+ * DBus communication
  */
 
 /**

spa/include/spa/support/i18n.h

@@ -33,7 +33,7 @@ extern "C" {
 #include <spa/utils/defs.h>
 
 /** \defgroup spa_i18n I18N
- *
+ * Gettext interface
  */
 
 /**

spa/include/spa/support/log.h

@@ -36,6 +36,7 @@ extern "C" {
 #include <spa/utils/hook.h>
 
 /** \defgroup spa_log Log
+ * Logging interface
  */
 
 /**

spa/include/spa/support/loop.h

@@ -34,7 +34,7 @@ extern "C" {
 #include <spa/support/system.h>
 
 /** \defgroup spa_loop Loop
- *
+ * Event loop interface
  */
 
 /**

spa/include/spa/support/plugin-loader.h

@@ -33,7 +33,7 @@ extern "C" {
 #include <spa/utils/defs.h>
 
 /** \defgroup spa_plugin_loader Plugin Loader
- *
+ * SPA plugin loader
  */
 
 /**

spa/include/spa/support/plugin.h

@@ -34,6 +34,7 @@ extern "C" {
 
 /**
  * \defgroup spa_handle Plugin Handle
+ * SPA plugin handle and factory interfaces
  */
 
 /**

spa/include/spa/support/system.h

@@ -38,7 +38,7 @@ struct itimerspec;
 #include <spa/utils/hook.h>
 
 /** \defgroup spa_system System
- *
+ * I/O, clock, polling, timer, and signal interfaces
  */
 
 /**

spa/include/spa/support/thread.h

@@ -37,7 +37,7 @@ extern "C" {
 #include <spa/utils/dict.h>
 
 /** \defgroup spa_thread Thread
- *
+ * Threading utility interfaces
  */
 
 /**