github: update the new doc issue template to redirect the user to the new location

Signed-off-by: Hofi <[email protected]>

Author: HofiOne

.github/ISSUE_TEMPLATE/20-documentation-issue.md

@@ -1,10 +1,10 @@
 ---
 name: Documentation issue
-about: Please use https://github.com/syslog-ng/syslog-ng.github.io/issues/new/choose.
+about: Please use [https://github.com/syslog-ng/syslog-ng.github.io/issues/new/choose](https://github.com/syslog-ng/syslog-ng.github.io/issues/new/choose).
 title: ''
 labels: 'doc-bug'
 assignees: ''
 
 ---
 
-Documentation issues are now handled in the new Documentation Center issue tracker. Please [use that](https://github.com/syslog-ng/syslog-ng.github.io/issues/new/choose) instead.
+Documentation issues are now handled in the new Documentation Center issue tracker. Please use https://github.com/syslog-ng/syslog-ng.github.io/issues/new/choose instead.