If you really just want a plain text representation of this, which will remove all hyperlinking functionality etc., then I guess the easiest manual solution would be to use an existing wiki. You can just edit any page, paste your code in, press preview (don’t save please!) and then you get the parsed representation of the wiki text. You can then copy paste that and paste it into a text editor.
Otherwise, if you don’t want to lose any formatting, then you could either copy the resulting HTML, or just keep the wiki text as it is. This makes especially sense if there are more complicated structures within, e.g. tables or template calls.