Add single database configuration instructions (#37)

* Add single database configuration instructions

* Update README.md

Co-authored-by: Nick Pezza <pezza@hey.com>

* Update README.md

Co-authored-by: Nick Pezza <pezza@hey.com>

---------

Co-authored-by: Nick Pezza <pezza@hey.com>

Author: jimmypoulsen

README.md

@@ -4,7 +4,7 @@ Solid Cable is a database-backed Action Cable adapter that keeps messages in a t
 
 > [!NOTE]
 > Solid Cable is tested to work with MySQL, SQLite, and PostgreSQL.
-> 
+>
 > Action Cable already has a [dedicated PostgreSQL adapter](https://guides.rubyonrails.org/action_cable_overview.html#postgresql-adapter),
 > which utilizes the builtin `NOTIFY` command for better performance. However, that
 > adapter has an 8kb limit on its payload. Solid Cable is a great alternative if you find yourself
@@ -52,6 +52,16 @@ production:
 
 Then run `db:prepare` in production to ensure the database is created and the schema is loaded.
 
+### Single database configuration
+
+Running Solid Cable in a separate database is recommended, but it's also possible to use a single database for both the app and Action Cable.
+
+1. Copy the contents of `db/cable_schema.rb` into a normal migration and delete `db/cable_schema.rb`
+2. Remove `connects_to` from `config/cable.yml`
+3. `bin/rails db:migrate`
+
+You won't have multiple databases, so `database.yml` doesn't need to have primary and cable database.
+
 ## Configuration
 
 All configuration is managed via the `config/cable.yml` file. By default, it'll be configured like this: