Links to Markown Cheatsheet outdated

[menschenkind]

Description

The Markdown cheatsheet PDF link in issue templates 1, 2, 3, and 4 is outdated and should be updated to the correct version. Steps to reproduce

• Open issue template 1, 2, 3, or 4.
• Scroll to the section with the Markdown cheatsheet link.
• Click the link → it points to a missing PDF.

Expected behavior

The link should point to the current Markdown cheatsheet PDF.

Links to the affected lines

• issue1.md#L15
• issue2.md#L15
• issue3.md#L15
• issue4.md#L14

:wave: I would like to provide a fix.