refactor(scss/project/mosaic2): decouples header element
improve(stratups/): highlights what is the main heading
improve(startups): simplifies intro item slicing
improve(startups): glues arrow to the text
refactor(scss/project/mosaic2): simplifies textual intro/outro blocks
typo(startups): `rr` -> `r`
improve(startups): typogrifies line
improve(startups): makes entire intro item clickable