docs: added HACKING file

HACKING

@@ -0,0 +1,14 @@
+Code formating and ordering
+
+* The source file will keep and order of methods. The order will be as
+following:
+  1. Private functions will go first.
+  2. class_init and init will go second.
+  3. vfuncs implementations will go third.
+  4. Public API will go fourth
+
+* Methods naming will be according to:
+  1. Private methods will have no prefix
+  2. vfuncs and public API will have the right prefix
+
+* The methods prototype will always be placed at the top of the source.

Makefile.am

@@ -19,6 +19,7 @@ EXTRA_DIST =                    \
   $(INTLTOOL_FILES)             \
   INSTALL                       \
   THANKS                        \
+  HACKING                       \
   TODO                          \
   autogen.sh