docs: Fix broken README links, appease markdown linter

README.md

@@ -15,7 +15,7 @@
 
 ## Basic usage
 
-1. Set up Docker Swarm and [`abra`][abra]
+1. [Set up Docker Swarm and `abra`][operators-tutorial]
 2. Deploy [`coop-cloud/traefik`][cc-traefik]
 3. `abra app new gitea --secrets` (optionally with `--pass` if you'd like
    to save secrets in `pass`)
@@ -23,6 +23,9 @@
    your Docker swarm box
 5. `abra app deploy YOURAPPDOMAIN`
 
+[operators-tutorial]: https://docs.coopcloud.tech/operators/tutorial/
+[cc-traefik]: https://git.coopcloud.tech/coop-cloud/traefik/
+
 ## Create first user
 
 Run
@@ -36,25 +39,34 @@ See the [Gitea command-line documentation](https://docs.gitea.io/en-us/command-l
 ## Enable SSH
 
 You most certainly want to be able to access your repository over SSH.  To do so, make sure you uncomment the right lines in the configuration for `traefik`.
-```
+
+```sh
 abra app config YOURTRAEFIKAPP
 ```
+
 There uncomment or add these lines:
-```
+
+```sh
 GITEA_SSH_ENABLED=1
 COMPOSE_FILE="compose.yml:compose.gitea.yml"
 ```
+
 Then redeploy traefik:
-```
+
+```sh
 abra app undeploy YOURTRAEFIKAPP
 abra app deploy YOURTRAEFIKAPP
 ```
+
 You might need to wait a bit.  To check if it worked, you can run
-```
+
+```sh
 telnet my.gitea.example.com 2222
 ```
+
 Once you have added a public SSH key, you can check that you can connect to your gitea server with
-```
+
+```sh
 ssh -T -p 2222 git@my.gitea.example.com
 ```