Terribly inconvenient for actual usage. To use links on your site, I need to highlight expressions in brackets by mouse (and I need to click-and-drag, and I need to be exact at it), then I need to copy this value, parse relative links, and paste it in appropriately.

Unusable from a keyboard (on a standard configuration of Firefox at least; I suppose there’s an option to allow for more precise highlighting from a keyboard). Probably unusable for visually impaired users, definitely not pleasant to listen to.

If you want minimalism, fine, but you should use basic HTML (like the HTML you’d get from any Markdown renderrer and your .txt files…). With clickable links, Tab-and-hit-Enter links, visually-impaired-friendly links, and so on.