This page is for typing emails with consistent formatting. It uses the open source Quill text editor, configured to only allow a small set of basic formatting options. I find this particularly useful when composing emails with sections pasted from other places: the editor only pastes the text with permitted formatting.
This page runs entirely in your browser—what you type is not sent to the internet. This means that what you type is not saved anywhere. When you're done you'll need to copy and paste it into your email application.
You are free to use the source code of this page however you like. I've configured the editor for my use case, but if your use case requires different formatting options available, you are most welcome to copy it somewhere and edit it to suit your needs.
—talljosh, March 2020