Add FAQ entry on which database to use

Fixes: #2257

docs/about/faq.md

@@ -44,6 +44,18 @@ For convenience, we also [build Docker images with headscale](../setup/install/c
 we don't officially support deploying headscale using Docker**. On our [Discord server](https://discord.gg/c84AZQhmpx)
 we have a "docker-issues" channel where you can ask for Docker-specific help to the community.
 
+## Which database should I use?
+
+We recommend the use of SQLite as database for headscale:
+
+- SQLite is simple to setup and easy to use
+- It scales well for all of headscale's usecases
+- Development and testing happens primarily on SQLite
+- PostgreSQL is still supported, but is considered to be in "maintenance mode"
+
+The headscale project itself does not provide a tool to migrate from PostgreSQL to SQLite. Please have a look at [the
+related tools documentation](../ref/integration/tools.md) for migration tooling provided by the community.
+
 ## Why is my reverse proxy not working with headscale?
 
 We don't know. We don't use reverse proxies with headscale ourselves, so we don't have any experience with them. We have

docs/ref/integration/tools.md

@@ -8,5 +8,6 @@
 This page collects third-party tools and scripts related to headscale.
 
 | Name                  | Repository Link                                                 | Description                                       |
-| ----------------- | --------------------------------------------------------------- | ------------------------------------------------- |
+| --------------------- | --------------------------------------------------------------- | ------------------------------------------------- |
 | tailscale-manager     | [Github](https://github.com/singlestore-labs/tailscale-manager) | Dynamically manage Tailscale route advertisements |
+| headscalebacktosqlite | [Github](https://github.com/bigbozza/headscalebacktosqlite)     | Migrate headscale from PostgreSQL back to SQLite  |