Fleet Footwork instead of Press the Attack. Legend: Alacrity instead of Legend: Bloodline. Should take those runes and get either Ninja Tabi or Mercury's Treads instead of Berserker's Greaves. That increases overall survivability and doesn't really cost much on the damage end of things. Everything else looks fine as far as the build goes. I only suggest taking Cut Down if you know for a fact you're going to be against a tankier lane opponent, as it isn't very good right now otherwise. That recommendation will likely change/not matter in patch 8.2. As for the guide itself, many sections lack a vivid description. Champion matchups is very small and not very descriptive. In items, it's not ALWAYS best to rush Phantom Dancer, a high burst AP mage/assassin will usually call for a Hexdrinker rush then Phantom Dancer. Your advice on farming is nice and I don't see it specifically pointed out in most guides. I think the better phrasing is that they should look to get at least 70 CS at 10 minutes, at least 170 at 20 minutes, and at least 260 at 30 minutes. It might also have been a good idea to express that, despite needing to have good farm, you should be careful about shoving the wave too quickly, especially in top lane as it is a long lane and can leave you very vulnerable to ganks, even if you have the river bush warded. The combo section is pretty good. The Pro's and Con's are also pretty good.

On another note, if you're building Trinity Force you should almost always also get a Sterak's Gage and a Frozen Mallet. If you're top lane, you almost always want a Frozen Mallet, except in very rare cases. You should also add Mercurial Scimitar as an item option against hard CC.