doc: README: Add more information about postgres setup

README.md

@@ -3,7 +3,14 @@
 ## Setup
 * clone the project
 * install geoip and postgres from your local package manager
-* setup av venv
+* setup postgres on your machine, see e.g. https://wiki.archlinux.org/title/PostgreSQL
+  * `$ sudo su postgres`
+  * `$ initdb -D /var/lib/postgres/data`
+* start postgres
+* create postgres user
+  * `$ sudo su postgres`
+  * `$ createuser --interactive` -> owl
+* setup a venv
 * enter the venv
 * run 'pip install -r requirements.txt'
 * cp config/examply.py config/default.py