docs: create midgard postgresql documentation

midgard/postgresql.md

@@ -0,0 +1,21 @@
+# [midgard] PostgreSQL
+
+## Installation
+
+`sudo curl -o /etc/apt/trusted.gpg.d/pgdg.asc https://www.postgresql.org/media/keys/ACCC4CF8.asc`
+
+`echo "deb [signed-by=/etc/apt/trusted.gpg.d/pgdg.asc] https://apt.postgresql.org/pub/repos/apt $(lsb_release -cs)-pgdg main" | sudo tee /etc/apt/sources.list.d/pgdg.list`
+
+`sudo apt update`
+
+`sudo apt install postgresql-16`
+
+## Configuration
+
+`sudo chown postgres:postgres /data/pgdata /data/pglog`
+
+`sudo pg_dropcluster --stop 16 main`
+
+`sudo pg_createcluster -d /data/pgdata/16/midgard -l /data/pglog/postgresql-16-midgard.log 16 midgard`
+
+`sudo pg_ctlcluster start 16 midgard`