This is the source code for a tool that takes markdown format, and outputs html formatted in the way compatible with the medium.com editor.
The tool is hosted on surge: http://markdown-to-medium.surge.sh/
I made it for myself, so I can take my personal blog posts, written in markdown, paste them in here and copy the output to Medium when adding the post there.
Medium does have a function to import posts, but it always fails miserably with the formatting.
There is only one option in the menu currently, and that is how to format inline codespans, there isn't quite any equivalent of these in a Medium post so you can select if you want to translate those to bold, italic, or with double quotes " around them (or all of the above which is what I normally do).
The project is based on Create React App, so if you want to build it locally and change things the setup is basically:
npm install
npm start
That will build and server the project on http://localhost:3000.
npm run build will make an optimized production build into the build directory.