Documentation: Link to MW docs (rel. 1.23).

Doxyfile

@@ -169,7 +169,7 @@ SHORT_NAMES            = NO
 # description.)
 # The default value is: NO.
 
-JAVADOC_AUTOBRIEF      = NO
+JAVADOC_AUTOBRIEF      = YES
 
 # If the QT_AUTOBRIEF tag is set to YES then doxygen will interpret the first
 # line (until the first dot) of a Qt-style comment as the brief description. If
@@ -743,7 +743,7 @@ WARN_LOGFILE           =
 # spaces.
 # Note: If this tag is empty the current directory is searched.
 
-INPUT                  = ../../
+INPUT                  = 
 
 # This tag can be used to specify the character encoding of the source files
 # that doxygen parses. Internally doxygen uses the UTF-8 encoding. Doxygen uses
@@ -1008,7 +1008,7 @@ GENERATE_HTML          = YES
 # The default directory is: html.
 # This tag requires that the tag GENERATE_HTML is set to YES.
 
-HTML_OUTPUT            = ../
+HTML_OUTPUT            = gh-pages
 
 # The HTML_FILE_EXTENSION tag can be used to specify the file extension for each
 # generated HTML page (for example: .htm, .php, .asp).
@@ -1352,7 +1352,7 @@ DISABLE_INDEX          = NO
 # The default value is: NO.
 # This tag requires that the tag GENERATE_HTML is set to YES.
 
-GENERATE_TREEVIEW      = NO
+GENERATE_TREEVIEW      = YES
 
 # The ENUM_VALUES_PER_LINE tag can be used to set the number of enum values that
 # doxygen will group on one line in the generated HTML documentation.
@@ -1973,7 +1973,7 @@ SKIP_FUNCTION_MACROS   = YES
 # the path). If a tag file is not located in the directory in which doxygen is
 # run, you must also specify the path to the tagfile here.
 
-TAGFILES               =
+TAGFILES               = "Doxygen_mwtags.xml = https://doc.wikimedia.org/mediawiki-core/REL1_23/php/html"
 
 # When a file name is specified after GENERATE_TAGFILE, doxygen will create a
 # tag file that is based on the input files it reads. See section "Linking to