Update README.markdown

Add cmake dependency
clear terminal backlog in ++prep
Merge branch 'master' of https://github.com/urbit/urbit
clean for new era
updated dependency list
general cmark cleanup
remove markdown printfs
Show the how of a bail in more cases.
Merge pull request #207 from gkelly/show-bail-before-abort

Show the how of a bail in more cases.
move markdown jet to u3a_calloc
fix sync memory leak on linux
md content type update
Moved entity parser to %zuse, cleanup
Merge branch 'master' of https://github.com/urbit/urbit
Merge branch 'master' of github.com:urbit/urbit
Split mar/down, installed jet hoon-spec
Merge branch 'master' of https://github.com/urbit/urbit
fix markdown jet memory leak
Merge branch 'master' of https://github.com/urbit/urbit
fix some of ford's blocking problems