Missing stuff in Proofmode.md.

Thanks to Janno for spotting this!
2 jobs for master in 16 minutes and 31 seconds (queued for 11 minutes and 18 seconds)
Status Job ID Name Coverage
  Test
passed #2246
coq
iris-coq8.5.3

00:06:08

passed #2247
coq
iris-coq8.6

00:10:22