Fix a typo on Almanac User Guide
Summary:
Ref T10527
The lack of a * messed up the remarkup.
Test Plan:
Tested on my instance by pasting the sentence in a phriction document.
See the markup correctly done.
Reviewers: epriestley, #blessed_reviewers
Reviewed By: epriestley, #blessed_reviewers
Subscribers: Korvin
Maniphest Tasks: T10527
Differential Revision: https://secure.phabricator.com/D15421