Changes:
    748d3c161 Add usage recommendations to README.md
    2939fcfed Replace marl::parallelize()
    4b4600208 Fix stupid typo in front page code samples.
    742bba9c8 Fix clang-tidy and go-vet warnings.

Commands:
    ./third_party/update-marl.sh --squash

Bug: b/140546382
Change-Id: Ia8226c11bafbf40907a4622cfdfae3cdcdc303ba