Replace <code> with <kbd> on /about
Replace <code> with <kbd> on /about

<kbd> is the correct element for this piece of content.

Change-Id: I7799f90f0e7c637f39d7788c252ad2ccf93472b0

diffux/diffux,kalw/diffux,kalw/diffux,diffux/diffux,diffux/diffux,kalw/diffux