Did reading the text help you any? Did the word "wiki" make sense in the context? (I suppose "lambda", "lisp", and "s-expression" are not very familiar to you?)
No snark here, I just try to understand how do different people read and understand a copy like this.
Ah, the page I saw initially was pretty self-explanatory, a wiki page describing things like `{b{i{Hello World}}}` and all the way to introducing basic Lisp constructs.
It is now taken offline due to too many "stupid people", as the last line says, apparently due to them vandalizing it :(
The menu which is shown now is much less helpful indeed.
tldr; - Think of Wikipedia. Even though it’s a web site with html, people who make edits do not create html. Instead they edit this nasty quasi-text document bearing a vague resemblance to markdown. This seems to be intended for a similar purpose in wikis.
post tldr - The terrible thing was this was painful to use and early on wikis had almost no structured data. So you have incredible amounts of useful information that mostly cannot be leveraged or processed efficiently because it’s a living nightmare to parse.
Over time things have improved. They added a wysiwyg editor so you don’t have to look at it. They’ve incrementally added ways to allow for documents and data to be more structured and parsable.
No snark here, I just try to understand how do different people read and understand a copy like this.