Fix YAML block (ỳaml -> yaml)

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/2089

docs/configuring-playbook-cactus-comments.md

@@ -13,7 +13,7 @@ does and why it might be useful to you.
 
 Add the following block to your `vars.yaml` and make sure to exchange the tokens to randomly generated values.
 
-```ỳaml
+```yaml
 #################
 ## Cactus Chat ##
 #################