doc: Add custom main page for API docs

Doxyfile

@@ -10,7 +10,7 @@ HIDE_SCOPE_NAMES       = YES
 SHOW_INCLUDE_FILES     = NO
 WARN_NO_PARAMDOC       = YES
 WARN_AS_ERROR          = $(DOXYGEN_WARN_AS_ERROR)
-INPUT                  = $(SOURCE_ROOT)README.md \
+INPUT                  = $(SOURCE_ROOT)doc/mainpage.md \
                          $(SOURCE_ROOT)include/libxml/c14n.h \
                          $(SOURCE_ROOT)include/libxml/catalog.h \
                          $(SOURCE_ROOT)include/libxml/chvalid.h \
@@ -91,7 +91,7 @@ INPUT                  = $(SOURCE_ROOT)README.md \
                          $(SOURCE_ROOT)xmlwriter.c \
                          $(SOURCE_ROOT)xpath.c \
                          $(SOURCE_ROOT)xpointer.c
-USE_MDFILE_AS_MAINPAGE = $(SOURCE_ROOT)README.md
+USE_MDFILE_AS_MAINPAGE = $(SOURCE_ROOT)doc/mainpage.md
 EXCLUDE_SYMLINKS       = YES
 VERBATIM_HEADERS       = NO
 DISABLE_INDEX          = NO

doc/mainpage.md

@@ -0,0 +1,25 @@
+# API Documentation
+
+See [File List](files.html) for API documentation sorted by
+public header files.
+
+## About
+
+libxml2 is an XML toolkit implemented in C, originally developed for
+the GNOME Project.
+
+Official releases can be downloaded from
+<https://download.gnome.org/sources/libxml2/>
+
+The git repository is hosted on GNOME's GitLab server:
+<https://gitlab.gnome.org/GNOME/libxml2>
+
+Bugs should be reported at
+<https://gitlab.gnome.org/GNOME/libxml2/-/issues>
+
+Other documentation is available at
+<https://gitlab.gnome.org/GNOME/libxml2/-/wikis>
+
+## License
+
+This code is released under the MIT License, see the Copyright file.

doc/meson.build

@@ -4,7 +4,10 @@ doxygen = find_program('doxygen')
 
 doxygen_docs = custom_target(
     'Doxygen documentation',
-    input: [ xml_src_files, libxml_headers ],
+    input: [
+        xml_src_files, libxml_headers,
+        files('libxml2.css', 'mainpage.md'),
+    ],
     output: [ 'html', 'xml' ],
     command: [ doxygen, '-q', doxyfile ],
     env: {