Markdown is a good default for writing content that ends up on the web.
It’s readable as plain text, so you can edit it in any editor and keep it in version control. Formatting is minimal: headings, lists, links, code blocks. That keeps the focus on what you’re saying instead of layout tweaks.
Most static site generators and docs tools understand Markdown and can turn it into HTML. You can add metadata in front matter (YAML or TOML at the top of the file) for title, date, tags, and custom fields. One format works for blog posts, notes, and documentation.
If you need more structure later, you can still export or transform Markdown. For a personal site or blog, it’s usually enough.