Markdownlint: fenced-code-language

Author: mnocon

.markdownlint-cli2.yaml

@@ -24,7 +24,7 @@ config:
 # no-emphasis-as-heading: true
   no-space-in-code: true
   no-space-in-links: true
-# fenced-code-language: true
+  fenced-code-language: true
 # first-line-heading: true
 # ol-prefix: one_or_ordered
 # list-marker-space: true

docs/infrastructure_and_maintenance/cache/http_cache/reverse_proxy.md

@@ -149,7 +149,7 @@ If the Varnish server is protected by Basic Auth, specify the Basic Auth credent
 Varnish is enabled by default when using [[= product_name_cloud =]] and the `purge_servers` setting is set automatically. 
 To enable Basic Auth on [[= product_name_cloud =]] when using Varnish, specify the credentials using the following environment variables to make sure that Varnish is reachable:
 
-```
+``` bash
 env:HTTPCACHE_USERNAME=myuser
 env:HTTPCACHE_PASSWORD=mypasswd
 ```