evolve: fix some documentation grammar/typos

--HG--
branch : stable
7 jobs for topic/default/typo in 4 minutes and 45 seconds (queued for 1 second)
Status Name Job ID Coverage
  Test
passed doc #65823

00:00:39

passed flake8 #65817

00:00:35

manual pytype #65818
allowed to fail manual
passed tests-py2-cext #65819

00:04:41

passed tests-py2-pure #65820

00:03:31

failed tests-py3-cext #65821

00:03:26

failed tests-py3-pure #65822

00:04:44

 
Name Stage Failure
failed
tests-py3-pure Test
ERROR: test-wireproto.t output changed
!..............................
Failed test-evolve.t: output changed
Failed test-rewind.t: output changed
Failed test-touch.t: output changed
Failed test-wireproto.t: output changed
# Ran 171 tests, 0 skipped, 4 failed.
python hash seed: 3336089758
ERROR: Job failed: exit code 1
failed
tests-py3-cext Test
ERROR: test-evolve.t output changed
!
Failed test-evolve.t: output changed
Failed test-rewind.t: output changed
Failed test-touch.t: output changed
Failed test-wireproto.t: output changed
# Ran 171 tests, 0 skipped, 4 failed.
python hash seed: 1276844783
ERROR: Job failed: exit code 1