[DOCS]: MotherDuck additions (#3870)

Co-authored-by: Trey Spiller <1831878+treysp@users.noreply.github.com>

Author: mesmith027

docs/integrations/engines/motherduck.md

@@ -1,6 +1,96 @@
 # MotherDuck
 
+This page provides information about how to use SQLMesh with MotherDuck. 
+
+It begins with a [Connection Quickstart](#connection-quickstart) that demonstrates how to connect to MotherDuck, or you can skip directly to information about using MotherDuck with the built-in or airflow schedules.
+
+## Connection quickstart
+
+Connecting to cloud warehouses involves a few steps, so this connection quickstart provides the info you need to get up and running with MotherDuck.
+
+It demonstrates connecting to MotherDuck with the `duckdb` library bundled with SQLMesh. 
+
+MotherDuck provides a single way to authorize a connection. This quickstart demonstrates authenticating with a token.
+
+!!! tip  
+    This quick start assumes you are familiar with basic SQLMesh commands and functionality.
+
+    If you’re not familiar, work through the [SQLMesh Quickstart](../../quick_start.md) before continuing.  
+
+### Prerequisites
+
+Before working through this quickstart guide, ensure that:
+
+1. You have a motherduck account and an access token.  
+2. Your computer has SQLMesh installed with the DuckDB extra available.  
+   1. Install from command line with the command `pip install “sqlmesh[duckdb]”`  
+3. You have initialized a SQLMesh example project on your computer  
+   1. Open a command line interface and navigate to the directory where the project files should go.  
+   2. Initialize the project with the command `sqlmesh init motherduck`
+
+#### Access control permissions
+
+SQLMesh must have sufficient permissions to create and access your MotherDuck databases. Since permission is granted to specific databases for a specific user, you should create a service account for SQLMesh that will contain the credentials for writing to MotherDuck.
+
+### Configure the connection
+
+We now have what is required to configure SQLMesh’s connection to MotherDuck.
+
+We start the configuration by adding a gateway named `motherduck` to our example project’s config.yaml file and making it our `default gateway`, as well as adding our token, persistent, and ephemeral catalogs.
+
+```yaml  
+gateways:  
+    motherduck:  
+        connection:   
+            type: motherduck  
+            catalogs:  
+                persistent: ‘md:’  
+                ephemeral: ‘:memory:’  
+            token: \<your\_token\>
+
+default\_gateway: motherduck  
+```
+
+!!! warning
+    Best practice for storing secrets like tokens is placing them in [environment variables that the configuration file loads dynamically](../../guides/configuration.md#environment-variables). For simplicity, this guide instead places the value directly in the configuration file.
+
+    This code demonstrates how to use the environment variable `MOTHERDUCK_TOKEN` for the configuration's `token` parameter:
+
+    ```yaml linenums="1" hl_lines="5"
+    gateways:  
+        motherduck:  
+            connection:   
+                type: motherduck  
+            token: {{ env_var('MOTHERDUCK_TOKEN') }}
+    ```
+
+### Check connection
+
+We have now specified the `motherduck` gateway connection information, so we can confirm that SQLMesh is able to successfully connect to MotherDuck. We will test the connection with the `sqlmesh info` command.
+
+First, open a command line terminal. Now enter the command `sqlmesh info`:
+
+![](./motherduck/sqlmesh_info.png)
+
+The output shows that our data warehouse connection succeeded:
+
+![](./motherduck/info_output.png)
+
+### Run a `sqlmesh plan`
+
+Now we're ready to run a `sqlmesh plan` in MotherDuck:
+
+![](./motherduck/sqlmesh_plan.png)
+
+And confirm that our schemas and objects exist in the MotherDuck catalog:
+
+![](./motherduck/motherduck_ui.png)
+
+Congratulations \- your SQLMesh project is up and running on MotherDuck\!
+
+
 ## Local/Built-in Scheduler
+
 **Engine Adapter Type**: `motherduck`
 
 ### Connection options