Merge branch '574-docs-configuration-overwrites-source-suffixes' into 'master'

Resolve "docs configuration overwrites source suffixes"

Closes #574

See merge request lscsoft/bilby!963

docs/conf.py

@@ -48,8 +48,7 @@ templates_path = ['templates']
 # The suffix(es) of source filenames.
 # You can specify multiple suffix as a list of string:
 #
-source_suffix = ['.rst', '.md']
-source_suffix = ['.txt', ".rst", ".ipynb"]
+source_suffix = ['.rst', '.md', '.txt', '.ipynb']
 
 # The master toctree document.
 master_doc = 'index'