Rewrite the front page of the docs (#809)

This is another step towards having a clearer documentation. I
restructured the front page and added "sign posts" so users can
understand our documentation flow a bit better.

---------

Co-authored-by: Andrew Farries <[email protected]>

Author: kvch

docs/getting-started.md

@@ -1,6 +1,32 @@
-# Getting started
+# Welcome to pgroll's documentation
 
-This guide covers the key concepts of `pgroll` and how to get started with it.
+`pgroll` is a migration tool for PostgreSQL that makes it easy to apply schema changes safely, without application downtime. It supports instant rollbacks and helps ensure applications stay available during database schema changes by allowing applications to access different versions of your database schema.
+
+## Getting started
+
+Learn how `pgroll` simplifies zero-downtime migrations for you
+
+* [Why use pgroll](why-use-pgroll)
+* [Installation](installation)
+* [Concepts](concepts)
+* [Write your first migration](tutorial)
+
+## Guides
+
+Learn how to use `pgroll` in your developer workflow
+
+* [Integrate pgroll into your project](guides/clientapps)
+* [Use pgroll with ORMs](guides/orms)
+* [Writing up and down migrations](guides/updown)
+
+## Connect with us
+
+If you have questions reach out to us on our
+* [Discord server](https://xata.io/discord)
+* [Github Discussion board](https://github.com/xataio/pgroll/discussions)
+
+If you want to report issues or submit feedback visit
+* [Github Issues](https://github.com/xataio/pgroll/issues)
 
 ## Supported Postgres versions
 

docs/guides/clientapps.mdx

@@ -1,6 +1,6 @@
 # Integrate pgroll into your project
 
-`pgroll` maintains multiple versions of the database schema side-by-side. For more details see the [getting started page](docs/getting-started.md).
+`pgroll` maintains multiple versions of the database schema side-by-side. For more details see the [Concepts page](concepts).
 
 ## Client applications