docs: add initial docs, w/ quickstart

just the very basics to get things in place

docs/quickstart.rst

@@ -0,0 +1,71 @@
+
+=============
+ Quick Start
+=============
+
+.. highlight:: sh
+
+WuttaPOS is a `Python`_ app based on `Rattail`_.
+
+.. _Python: https://www.python.org/
+.. _Rattail: https://rattailproject.org/
+
+As such it requires a Rattail DB to already be established, containing
+data for users (cashiers), customers, products etc.  Getting all that
+setup is outside the scope of this guide; for more info see the
+`Rattail Manual`_.
+
+.. _Rattail Manual: https://rattailproject.org/docs/rattail-manual/
+
+Here we are focused only on getting the WuttaPOS app setup.
+
+
+Installation
+------------
+
+Make a virtual environment::
+
+   python -m venv /srv/envs/wuttapos
+
+Install the WuttaPOS package into it::
+
+   cd /srv/envs/wuttapos
+   bin/pip install WuttaPOS
+
+
+Configuration
+-------------
+
+Make a basic config file::
+
+   cd /srv/envs/wuttapos
+   bin/rattail make-config -T rattail -O app
+
+Then edit ``app/rattail.conf`` to suit your needs.  In particular you
+must specify the DB connection.
+
+
+Usage
+-----
+
+Now you can run the app::
+
+   cd /srv/envs/wuttapos
+   bin/wuttapos open
+
+
+Access Control
+--------------
+
+Note that the app will only allow a user to login to POS, if they have
+permissions specific to the POS, namely "ring sales"
+(``pos.ring_sales``).
+
+Once logged in, additional POS-specific permissions will determine
+whether the user may perform some actions, or not.  In the latter case
+the user may *initiate* the action but then another user
+(e.g. manager) must login to complete the action.
+
+All permissions must be managed externally, e.g. via your Rattail
+back-office web app.  WuttaPOS will honor them but does not expose a
+way to manage them.