FIX: Make docs compatible with rtd using index (#83)

* FIX: docs build

* FIX: readthedocs config for docs

* add RTD badge

* move intro to index for compat with rtd

Author: mmcky

docs/conf.py

@@ -5,7 +5,7 @@
 project = "sphinx-jupyterbook-latex"
 copyright = "2020, Executable Book Project"
 author = "Executable Book Project"
-master_doc = "intro"
+master_doc = "index"
 
 
 # -- General configuration ---------------------------------------------------