Adding Documentation for AppFit Destination

This is a new destination, so we copied the template and filled it out.
Please let us know if this looks good.

Author: Claude Ciocan

src/connections/destinations/catalog/appfit/index.md

@@ -0,0 +1,26 @@
+---
+title: Appfit (Actions) Destination
+---
+
+{% include content/plan-grid.md name="actions" %}
+
+[AppFit](https://appfit.io/?utm_source=segmentio&utm_medium=docs&utm_campaign=partners) integrates with Segment to help teams stay on top of their key business metrics. Successful teams look at their app metrics on a consistent basis and use that data to make decisions about their business.
+
+Connect AppFit to your Segment account and get a top level dashboard for your mobile phone. as well as weekly reminders to review your metrics. If you see a metric that doesn't look right, AppFit lets you flag it and add comments so everyone can discuss what's going on right from their phone.
+
+This destination is maintained by AppFit. For any issues with the destination, [contact their Support team](mailto:[email protected]).
+
+{% include content/ajs-upgrade.md %}
+
+## Getting started
+
+1. From the Segment web app, click **Catalog**, then click **Destinations**.
+2. Find the Destinations Actions item in the left navigation, and click it.
+3. Click **Configure AppFit**.
+4. Select an existing Source to connect to AppFit (Actions).
+
+{% include components/actions-fields.html %}
+
+To find your API key, go to the AppFit app and click on Connectors in the main menu. If you already have a Segment Destination connector created, you can click on it and find your API key there, otherwise you can create a new connector by clicking on "Create New Connector" and selecting "Segment Destination"
+
+---