add database docs

content/docs/self-hosted/database-adapter/make-your-own.md

@@ -5,4 +5,11 @@ prev: '/docs/self-hosted/database-adapter/mongodb'
 next: null
 ---
 
-TODO:
+The database adapter uses the [abstract level]() interface. To implement your own database adapter you will need to follow that interface.
+
+Here is some example of the ones we have built:
+
+- [upstash-redis-level](https://github.com/tinacms/upstash-redis-level)
+- [mongodb-level](https://github.com/tinacms/mongodb-level)
+
+TODO: add more details here

content/docs/self-hosted/database-adapter/mongodb.md

@@ -5,4 +5,33 @@ prev: '/docs/self-hosted/database-adapter/vercel-kv'
 next: '/docs/self-hosted/database-adapter/make-your-own'
 ---
 
-TODO:
+The MongoDB database adapter allows you to store your data in a [MongoDB](https://www.mongodb.com/) database. This adapter uses the [mongodb](https://www.npmjs.com/package/mongodb) so it will work on any MongoDB database.
+
+To get started you will need to add the following environment variables to your project:
+
+```env
+MONGODB_URI=***
+```
+
+## Create the database adapter
+
+```ts
+import { MongodbLevel } from 'mongodb-level'
+//...
+
+export default isLocal
+  ? createLocalDatabase()
+  : createDatabase({
+      // ...
+      databaseAdapter: new MongodbLevel<string, Record<string, any>>({
+        // If you wanted to use a different collection for each branch the branch name could be used as the collection name
+        collectionName: 'tinacms',
+        dbName: 'tinacms',
+        mongoUri: process.env.MONGODB_URI as string,
+      }),
+    })
+```
+
+```
+
+```

content/docs/self-hosted/database-adapter/overview.md

@@ -5,7 +5,20 @@ prev: null
 next: /docs/self-hosted/database-adapter/vercel-kv
 ---
 
-The database adapter is a wrapper around an existing data storage and handles indexing, listing and managing content.  We provide a two database adaptors out of the box:
+A database adapter is a module that allows you to store your data in a database of your choice. The database adapter is responsible for storing, retrieving and indexing data from and to the database. We currently have support for the following database adapters:
 
-* Vercel KV
-* MongoDB
+- [Vercel KV](/docs/self-hosted/database-adapter/vercel-kv)
+- [MongoDB](/docs/self-hosted/database-adapter/mongodb)
+
+With plans on supporting more in the future.
+
+Adding a database adapter can be done in the `database.{ts,js}` file by passing it to the `createDatabase` function.
+
+```ts
+// ...
+
+export isLocal ? createLocalDatabase() : createDatabase({
+    // ...
+    databaseAdapter: new DatabaseAdapter()
+})
+```

content/docs/self-hosted/database-adapter/vercel-kv.md

@@ -5,4 +5,34 @@ prev: '/docs/self-hosted/database-adapter/overview'
 next: '/docs/self-hosted/database-adapter/mongodb'
 ---
 
-TODO:
+The vercel KV database adapter allows you to store your data in the [Vercel KV](https://vercel.com/docs/concepts/projects#environment-variables). This adapter uses the [upstash redis client](https://www.npmjs.com/package/@upstash/redis) so will work on [upstash redis](https://docs.upstash.com/redis) as well.
+
+To get started you will need to add the following environment variables to your project:
+
+```env
+KV_REST_API_URL=***
+KV_REST_API_TOKEN=***
+```
+
+## Create the database adapter
+
+```ts
+//...
+import { RedisLevel } from 'upstash-redis-level'
+import { Redis } from '@upstash/redis'
+
+export default isLocal
+  ? createLocalDatabase()
+  : createDatabase({
+      // ...
+
+      databaseAdapter: new RedisLevel({
+        namespace: branch,
+        redis: new Redis({
+          url: process.env.KV_REST_API_URL || 'http://localhost:8079',
+          token: process.env.KV_REST_API_TOKEN || 'example_token',
+        }),
+        debug: process.env.DEBUG === 'true' || false,
+      }),
+    })
+```