New Backend Integration for Adonis JS (#546)

Adding [Adonis JS](https://github.com/adonisjs) integration under
backends.

A Framework by [Harminder Virk](https://github.com/thetutlage)

docs/integrations/backend/adonis.md

@@ -0,0 +1,31 @@
+---
+title: AdonisJS
+description: >-
+  A fully featured web framework for Node.js
+sidebar_position: 71
+---
+
+## Migrations
+
+Use the [`raw` method on the `Schema Builder`](https://docs.adonisjs.com/reference/database/schema-builder#raw).
+
+First, create a migration:
+
+```shell
+node ace make:migration electrify_items
+```
+
+Then use `this.schema.raw` in the `up` function:
+
+```javascript
+import BaseSchema from '@ioc:Adonis/Lucid/Schema'
+
+export default class extends BaseSchema {
+
+  public async up () {
+    this.schema.raw("ALTER TABLE items ENABLE ELECTRIC")
+  }
+
+}
+
+```