docs(cli): fix open command documentation typo (#716)

[clelange]

Fix typo that I spotted during the demo this morning.

[clelange]

Does this need an issue for commitlint to be happy?

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 58.62%. Comparing base (3465eb0) to head (9a4dfc2).

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #716   +/-   ##
=======================================
  Coverage   58.62%   58.62%           
=======================================
  Files          24       24           
  Lines        2393     2393           
=======================================
  Hits         1403     1403           
  Misses        990      990           

Files	Coverage Δ
reana_client/cli/workflow.py	63.73% <ø> (ø)

[tiborsimko]

Does this need an issue for commitlint to be happy?

We are attaching the PR number at the end, basically simulating GitHub's squash-merge behaviour. This is so that the PR would be linked in the Release-Please-compiled changelog items. Please see some details on the commit message here: https://github.com/reanahub/reana/wiki/Tips-for-Git#commit-message-style

No worries though, we can do these little cosmetic things while merging. E.g. in this case, I would suggest the commit log message:

docs(cli): fix `open` command documentation typo (#716)

(Note also the usage of docs instead of fix type, since this is a documentation-only change.)

I'll amend your PR in the above sense and merge.