[Sphinx Documentation] Change path to sources in conf.py

docs/finn/conf.py

@@ -12,7 +12,7 @@
 #
 import os
 import sys
-sys.path.insert(0, os.path.abspath('../../'))
+sys.path.insert(0, os.path.abspath('../../src/'))
 
 
 # -- Project information -----------------------------------------------------