Change the platforms list link to show the line with the actual platform list

[nekopsykose]

you should squash the commits since the second is a fixup

but i'm not sure how much i like line number links for master ref urls, when any lines change it will point to the wrong place. and if it uses a permalink with the full commit, it won't update itself if a 'platform' is added either.

perhaps platforms available [here](same url as now) in the PLATFORMS= variable is better