docs: Cleanup build warnings

docs/Doxyfile

@@ -302,6 +302,7 @@ EXPAND_ONLY_PREDEF     = YES
 PREDEFINED             = \
     $(ENV_DOXYGEN_DEFINES) \
     __attribute__(x)= \
+	_Static_assert(x, y) = \
     IDF_DEPRECATED(X)= \
     IRAM_ATTR= \
     configSUPPORT_DYNAMIC_ALLOCATION=1 \

docs/en/api-reference/bluetooth/esp_hf_ag.rst

@@ -1,14 +1,7 @@
 HFP AG API
 ==============
 
-Overview
---------
-
-`Instructions`_
-
-.. _Instructions: ../template.html
-
 API Reference
 -------------
 
-.. include:: /_build/inc/esp_hf_ag_api.inc
+.. include-build-file:: inc/esp_hf_ag_api.inc