docs: fix 1_Bug_report.yaml (#2319)

| Q | A |

|---------------|---------------------------------------------------------------------------------------------------------------------------|
| Bug fix? | yes/no |
| New feature? | yes/no <!-- please update src/**/CHANGELOG.md files -->
|
| Deprecations? | yes/no <!-- please update UPGRADE-*.md and
src/**/CHANGELOG.md files --> |
| Issues | Fix #... <!-- prefix each issue number with "Fix #", no need
to create an issue if none exists, explain below instead --> |

<!--
Replace this notice by a description of your feature/bugfix.
This will help reviewers and should be a good start for the
documentation.

Additionally:
 - Always add tests and ensure they pass.
- For new features, provide some code snippets to help understand usage.
-->

.github/ISSUE_TEMPLATE/1_Bug_report.yaml

@@ -26,9 +26,12 @@ body:
       description: Your generated JSON OpenApi documentation (`bin/console nelmio:apidoc:dump`)
     validations:
       required: true
-    value: ```json
-      - Add your JSON here (`bin/console nelmio:apidoc:dump`)
-      - ```
+    value: |
+        ```json
+
+        Replace this text with your JSON (`bin/console nelmio:apidoc:dump`)
+
+        ```
     render: markdown
   - type: textarea
     id: additional-context