Generated Makefile should allow easy change of build dir
Currently the generated Makefile uses './build/' as a build dir prefix. However in my projects I keep sphinx docs under '/docs/' but want to have the generated html documentation in '/build'. This can be accomplished by changing the Makefile.
However there are a lot of references to the build directory so you have to change each and every of them. It would be easier if there is just a variable which can be changed once.