Correct issue report guide link in issue template chooser

Contributor are presented with an issue template chooser page at the start of the issue creation process.

In addition to the issue report templates, some "contact links" provide information and links to other communication
channels. In order to encourage high quality issues, a link to the "issue report guide" is included on this page.

Previously that link pointed to an incorrect URL, resulting in a 404 error for those who visited it. The URL is hereby
corrected.

Author: per1234

.github/ISSUE_TEMPLATE/config.yml

@@ -9,7 +9,7 @@ contact_links:
     url: https://forum.arduino.cc/
     about: We can help you out on the Arduino Forum!
   - name: Issue report guide
-    url: https://github.com/arduino/arduino-ide/blob/main/docs/issues.md#issue-report-guide
+    url: https://github.com/arduino/arduino-ide/blob/main/docs/contributor-guide/issues.md#issue-report-guide
     about: Learn about submitting issue reports to this repository.
   - name: Contributor guide
     url: https://github.com/arduino/arduino-ide/blob/main/docs/CONTRIBUTING.md#contributor-guide