chore: add vdf dependency

docs/sphinx/README.md

@@ -0,0 +1,22 @@
+## Dependencies:
+
+```
+pip install -r requirements.txt
+```
+
+## Setup:
+
+1. Modify `source/conf.py`.
+2. Add .rst pages to `source` tree.
+
+## Build
+
+```
+$ mkdir build
+$ sphinx-build -M html source build -a
+```
+
+## Publish
+Export contents of `build/html` to host.
+
+N.B. For GitHub, touch `.nojekyll` file on the root of the branch.