I love Markdown. It's a format that you can use on any platform that plain text files work, it's simple to learn, and there are thousands of tools for every possible thing you might want to do with it. I even wrote my university dissertation in Markdown.
These are the tools I use when writing Markdown:
Strikethrough on Github is one or two tildes, but the Github Flavored Markdown spec has it as two. I spent a while wondering why Eleventy didn't support strikethrough. John Gruber wrote about strikethrough here which was never in his original Markdown spec.
// on Github
~this will strikethrough~
~~this will also strikethrough~~
// basically anywhere other markdown library
~~this will strikethrough~~
- Markdown Guide
- Mastering Markdown · GitHub Guides
- Create a Table in Markdown with No Headers
- nvUltra - Searchable, portable, MultiMarkdown notes
- Notable - The Markdown-based note-taking app that doesn't suck
- Mark Text - Markdown Editor
- A Markdown Editor for the 21st Century | Zettlr
- Nota — Pro writing app designed for local Markdown files.