Add documentation

library/apply_macros.yap

@@ -1,4 +1,4 @@
-%   File   : apply_macros.yap
+/%   File   : apply_macros.yap
 %   Author : E. Alphonse from code by Joachim Schimpf
 %   Updated: 15 June 2002
 %   Purpose: Macros to apply a predicate to all elements
@@ -6,6 +6,29 @@
 
 :- module(apply_macros, []).
 
+/** @defgroup apply_macros Apply Interface to maplist
+@ingroup library
+@{
+
+This library provides a SWI-compatible set of utilities for applying a
+predicate to all elements of a list.
+
+The apply library just forwards
+definitions to the @ref maplist library, these include:
+
+  - maplist/2,
+  - maplist/3,
+  - maplist/4,
+  - maplist/5,
+  - include/3,
+  - exclude/3,
+  - partition/4,
+  - partition/5
+
+@}
+
+*/
+
 :- reexport(maplist).
 
 :- reexport(mapargs).