Add instructions to setup PostgreSQL

data/guides.yml

@@ -60,6 +60,9 @@ categories:
       - path: associations
       - path: use-your-own-orm
         title: Use Your Own ORM
+  - path: database-configuration
+    pages:
+      - path: overview
   - path: migrations
     pages:
       - path: overview

source/guides/database-configuration/overview.md

@@ -0,0 +1,40 @@
+---
+title: Guides - Database Configuration Overview
+---
+
+# Overview
+
+Before starting your server, you need to configure database link in <code>.env*</code> files.
+
+Open this file for each environment and update <code>DATABASE_URL</code> for your database.
+
+## <a href="http://www.postgresql.org/" target="_blank">PostgreSQL</a>
+
+Setup database variable for the development environment:
+
+```
+# .env.development
+DATABASE_URL="postgres://username:password@localhost/bookshelf_development"
+```
+
+Setup database variable for the test environment:
+
+```
+# .env.test
+DATABASE_URL="postgres://username:password@localhost/bookshelf_test"
+```
+
+## Prepare tables in database
+
+After your database variables setup is done you need to create a table in your database before you're be able to launch a development server.
+In your terminal, enter:
+
+```
+% bundle exec hanami db prepare
+```
+
+To create a table in database for the test environment, enter:
+
+```
+% HANAMI_ENV=test bundle exec hanami db prepare
+```