Markdown links and reference definitions
Markdown is a lightweight, readable markup language for writing structured documents.
A Markdown link can be an autolink, e.g. <https://example.com>, an inline link like [The user will see this](https://example.com), or a reference-style link: [The user will see this][thisisthelabel].
A reference-style link requires a reference definition with a matching label thisisthelabel: https://example.com/ on a separate line.