Run the executable, copy/cut markdown to your clipboard and press F4 to format GitHub markdown to html.
With the following image markdown in your clipboard:
Hitting F4 will convert it into:
<img src="https://user-images.githubusercontent.com/4502154/142855066-c3258e9b-3a26-4855-8e83-5a5d6754536a.png" width=100 />
With the following url markdown in your clipboard:
[/enterprise/custom-messages](https://11112-enterprise.stackoverflow.cloud/enterprise/custom-messages)
Hitting F4 will convert it into:
<a href="https://11112-enterprise.stackoverflow.cloud/enterprise/custom-messages">/enterprise/custom-messages</a>