docs: migrated line highlighting to highlight-line, highlight-start, highlight-end#10202

Merged

DSchau merged 6 commits intogatsbyjs:masterfrom nero2009:fix/migrate-highlighting

Dec 7, 2018

+2,150-163

Commits on Nov 29, 2018

migrated line highlighting to highlight-line, highlight-start, highlight-end
nero-adaware
committed

Commits on Dec 7, 2018

Merge remote-tracking branch 'upstream/master' into fix/migrate-highlighting
DSchau
committed