Document how to use Poetry

Document how to use Poetry for setting up a dev environment and for
building & publishing a new release.

Author: sybrenstuvel

README.md

@@ -24,7 +24,20 @@ licensed under the [Apache License, version 2.0](https://www.apache.org/licenses
 
 ## Security
 
-
 Because of how Python internally stores numbers, it is very hard (if not impossible) to make a pure-Python program secure against timing attacks. This library is no exception, so use it with care. See https://securitypitfalls.wordpress.com/2018/08/03/constant-time-compare-in-python/ for more info.
 
+## Setup of Development Environment
+
+```
+python3 -m venv .venv
+. ./.venv/bin/activate
+pip install poetry
+poetry install
+```
+
+## Publishing a New Release
 
+```
+. ./.venv/bin/activate
+poetry publish --build
+```