Add self hosting docs (#34)

* Add self host docs

* Add more documentation

apps/docs/get-started/create-aws-credentials.mdx

@@ -0,0 +1,38 @@
+---
+title: Create AWS credentials
+description: Step by step guide to create AWS credentials to self-host Unsend.
+---
+
+<Steps>
+  <Step title="Create a new user">
+    Login to your AWS console and go to IAM > Users > Create user. Type in user name, in this case `unsend`
+
+    ![create user](/images/aws/key-1.png)
+
+  </Step>
+  <Step title="Set permission and create">
+    Search for `AmazonSNSFullAccess` and `AmazonSESFullAccess` and check the checkboxes. Then proceed to create the user.
+
+    ![set permission](/images/aws/key-2.png)
+
+  </Step>
+  <Step title="Create access key">
+    Click on the created user and click on the `Create access key` button.
+
+    ![create access key](/images/aws/key-3.png)
+    ![option and create](/images/aws/key-4.png)
+    ![description](/images/aws/key-5.png)
+
+  </Step>
+  <Step title="Retrieve access key">
+    Copy the access key ID and secret access key to your `.env` file.
+
+      ```env
+    AWS_ACCESS_KEY_ID=<access-key-id>
+    AWS_SECRET_ACCESS_KEY=<secret-access-key>
+    ```
+
+    ![create access key](/images/aws/key-6.png)
+
+  </Step>
+</Steps>