Let git ignore generated HTML also in the root directory.
tree2b5480416eb32a0c8b1e9dc849e75a63ad2787e4
-rw-r--r-- 188 .gitignore
drwxr-xr-x - docutils
drwxr-xr-x - prest
drwxr-xr-x - sandbox
drwxr-xr-x - web