Improve documentation example in styleguide

doc/development/documentation/styleguide/index.md

@@ -207,9 +207,9 @@ Some examples fail if incorrect capitalization is used:
 Additionally, commands, parameters, values, filenames, and so on must be
 included in backticks. For example:
 
-- "Change the `needs` keyword in your `.gitlab.yml`..."
-  - `needs` is a parameter, and `.gitlab.yml` is a file, so both need backticks.
-    Additionally, `.gitlab.yml` without backticks fails markdownlint because it
+- "Change the `needs` keyword in your `.gitlab-ci.yml`..."
+  - `needs` is a parameter, and `.gitlab-ci.yml` is a file, so both need backticks.
+    Additionally, `.gitlab-ci.yml` without backticks fails markdownlint because it
     does not have capital G or L.
 - "Run `git clone` to clone a Git repository..."
   - `git clone` is a command, so it must be lowercase, while Git is the product,