Editor for markdown blog posts in Gatsby

Hi Everybody,

I am currently creating a blog for my website with Gatsby. I am familiar with creating markdown files and committing them but I want to enable some team members as well to create these files and see the output.

Is there anything (maybe self-hosted) like that out there?
Basically what I need is:

• WYSIWYG editor for markdown
• Capability to commit and push directly to a repository

I know that netlify and some other jamstack CMS are offering these solutions but I try to keep the costs as low as possible.

Thanks for your help!