Feature request: Add lef support to highlight standard cells

[mattvenn]

This is awesome!

See the work I'm doing here: https://tinytapeout.com

Just tried it on my GitHub action here: https://github.com/mattvenn/tinytapeout-7seg-seconds-counter/actions/runs/2913772759

It would be great to pass a lef as well and then all the standard cells could be highlighted and named. Great for exploring the gds.