fix code block not displaying properly (#7743)

Co-authored-by: Michael Kriese <michael.kriese@visualon.de>

docs/usage/config-presets.md

@@ -165,9 +165,9 @@ To host your preset config on GitHub:
 - Add configuration files to this new repo for any presets you want to share. For the default preset, `default.json` will be checked first and then `renovate.json`. For named presets, `<preset-name>.json` will be loaded. For example, loading preset `library` would load `library.json`. No other files are necessary.
 - In other repos, reference it in an extends array like "github>owner/name", for example:
 
-  ```json
-    "extends": ["github>rarkins/renovate-config"]
-  ```
+```json
+  "extends": ["github>rarkins/renovate-config"]
+```
 
 From then on Renovate will use the renovate config from the preset repo's default branch.
 You do not need to add it as a devDependency or add any other files to the preset repo.