Add postgres configuration to developer docs

Author: kbrock

developer_setup.md

@@ -96,7 +96,27 @@ ManageIQ requires a memcached instance for session caching and a PostgreSQL data
 
    * macOS
 
-     `brew` will configure the cluster automatically, but you will need to create the user.
+     `brew` will configure the cluster automatically, but you need to make a few tweaks
+     including granting access to the root user.
+
+     On apple silicone, postgres configuration is found in `/opt/homebrew` and intel is in `usr/local/homebrew`.
+
+     ```conf
+     # /opt/homebrew/var/postgresql@13/postgresql.conf
+     # right after authentication_timeout = 1min
+     password_encryption = scram-sha-256
+     wal_level = logical
+     max_locks_per_transaction = 128
+     ```
+
+     ```conf
+     # /opt/homebrew/etc/postgresql@13/pg_hba.conf
+     local   all             all                                     scram-sha-256
+     # IPv4 local connections:
+     host    all             all             127.0.0.1/32            scram-sha-256
+     # IPv6 local connections:
+     host    all             all             ::1/128                 scram-sha-256
+     ```
 
      ```bash
      brew services start postgresql@13