Fix Broken ma1sd Playbook Documentation Link

Old link was pointing at 

`https://github.com/spantaleev/matrix-docker-ansible-deploy/blob/master/configuring-playbook-ma1sd.md` which 404s

New link at `https://github.com/spantaleev/matrix-docker-ansible-deploy/blob/master/docs/configuring-playbook-ma1sd.md`

README.md

@@ -54,7 +54,7 @@ Services that run on the server to make the various parts of your installation w
 | [Coturn](https://github.com/coturn/coturn) | ✓ | STUN/TURN server for WebRTC audio/video calls | [Link](docs/configuring-playbook-turn.md) |
 | [nginx](http://nginx.org/) | ✓ | Web server, listening on ports 80 and 443 - standing in front of all the other services. Using your own webserver [is possible](docs/configuring-playbook-own-webserver.md) | [Link](docs/configuring-playbook-nginx.md) |
 | [Let's Encrypt](https://letsencrypt.org/) | ✓ | Free  SSL certificate, which secures the connection to the Synapse server and the Element web UI | [Link](docs/configuring-playbook-ssl-certificates.md) |
-| [ma1sd](https://github.com/ma1uta/ma1sd) | x | Matrix Identity Server | [Link](configuring-playbook-ma1sd.md)
+| [ma1sd](https://github.com/ma1uta/ma1sd) | x | Matrix Identity Server | [Link](docs/configuring-playbook-ma1sd.md)
 | [Exim](https://www.exim.org/) | ✓ | Mail server, through which all Matrix services send outgoing email (can be configured to relay through another SMTP server) | - |
 | [Dimension](https://github.com/turt2live/matrix-dimension) | x | An open source integrations manager for matrix clients | [Link](docs/configuring-playbook-dimension.md) |
 | [Sygnal](https://github.com/matrix-org/sygnal) | x | Push gateway | [Link](docs/configuring-playbook-sygnal.md) |