@agusputra I agree with your suggestion about helper buttons. The open source project Rocket Chat has an unobtrusive way of hinting basic Markdown syntax.
Simply a line of greyed text that becomes regular text on mouseover
It might be useful to have something like this at the bottom of the editor input field.
Using the option "Allow users to upload regular files" question
How would I allow only specified extensions? I don't want users uploading just any ol file, it could be a virus being uploaded, who knows...
added an issue for this
Thanks! It is the right step toward allowing for images being saved on the server vs imgur. That's why I am using it among other reasons as well.