fix(reg-notify-github-with-api-plugin): fix short description style

[shimapon]

What does this change?

This change addresses an issue where the short description in reg-notify-github-with-api-plugin was not being properly rendered in the PR comments. I have fixed it to ensure it displays correctly as Markdown.

References

I referenced a similar fix made in reg-notify-gitlab-plugin to guide this implementation.

• https://github.com/reg-viz/reg-suit/pull/625
• It seems related to this issue: https://github.com/reg-viz/reg-suit/issues/626

Screenshots

In my project, the comments were being displayed like this with the current package:

What can I check for bug fixes?

Please briefly describe how you can confirm the resolution of the bug.

[Quramy]

Thanks!