Fix docker-compose syntax in quick-start. GH #1105 (#1169)

* Fix docker-compose syntax in quick-start. GH #1105

* use new mkdocs tabs

* fix indentation for tabs

Co-authored-by: nils måsén <nils@piksel.se>

docs/index.md

@@ -45,13 +45,16 @@ and restart it with the same options that were used when it was deployed initial
 the following command:
 
 === "docker run"
+
     ```bash
     $ docker run -d \
     --name watchtower \
     -v /var/run/docker.sock:/var/run/docker.sock \
     containrrr/watchtower
     ```
+
 === "docker-compose.yml"
+
     ```yaml
     version: "3"
     services:

mkdocs.yml

@@ -23,7 +23,8 @@ markdown_extensions:
         user: containrrr
         repo: watchtower
     - pymdownx.saneheaders
-    - pymdownx.tabbed
+    - pymdownx.tabbed:
+        alternate_style: true 
 nav:
    - 'Home': 'index.md'
    - 'Introduction': 'introduction.md'