init: adding additional script

Signed-off-by: Alexis Pentori <alexis@status.im>

README.md

@@ -24,12 +24,14 @@ postgres_ha_databases:
   - name: my-db
     user: my-user
     pass: my-pass
+    script: 'CREATE SCHEMA IF NOT EXIST example;' 
 
   - name: my-other-db
     user: my-other-user
     pass: my-other-pass
 ```
 The `user` field is optional. DB name is used by default.
+The field `script` is optional and allow to add commands to run when creating the database.
 
 Backup settings can be adjusted using:
 ```yaml

templates/init/databases.sql

@@ -13,4 +13,7 @@ LOCALE "{{ db.locale }}"
 TEMPLATE "{{ db.template }}"
 {% endif %}
 ;
+{% if 'script' in db %}
+{{ db.script }}
+{% endif %}
 {% endfor %}