fix markdown format on readme

5 jobs for branch/default in 2 minutes and 36 seconds (queued for 4 seconds)
Status Name Job ID Coverage
  Lint
passed black #463844
lint black

00:02:31

passed check-manifest #463846
lint check-manifest

00:02:34

passed flake8 #463843
lint flake8

00:02:28

passed mypy #463845
lint mypy

00:02:11

 
  Tests
passed py3 #463847
py3 tests

00:02:02