This implies that it is possible to code the original #Doom in a single webpage (probably as a #Javascrippled page of the usual inefficient and unaccessible kind)
Many people use Markdown not just because the formatting is convenient to write, but also because it is itself human-readable. Consequently, it's also used as a plain text alternative to e.g. HTML-rendered text. I read a lot of things in plain text, so I see plain Markdown frequently.
One of the worst things you can do for legibility is to place URLs inline---it obscures the text, especially if there's a lot of them. Instead, use a reference (ideally numeric), of the form "[foo][n]".
Then, rather than placing all URLs at the bottom of the document, please them below the paragraph that references them. Not only does this reduce scrolling, but it also allows easily copying/pasting portions of the text while keeping the references intact, which is especially convenient for quoting.
@xj9 OMG, this! A thousands times this! As I said to someone else the other day, you can invent the most elegant and efficient back-end you like. It it doesn't have a great UX that drives adoption and network effect, you might as well tattoo your source code on the side of a herd of elephants, and compile it by starting a stampede ;-P @jcbrand