docs: emphasize the note on commit message length calculation

Author: kevin1kevin1k

Diff for: docs/commit.md

@@ -44,6 +44,6 @@ An exception would be raised when the message length exceeds the limit.
 For example, `cz commit -l 72` will limit the length of commit messages to 72 characters.
 By default the limit is set to 0, which means no limit on the length.
 
-Note that the limit applies only to the first line of message.
+**Note that the limit applies only to the first line of the message.**
 Specifically, for `ConventionalCommitsCz` the length only counts from the type of change to the subject,
 while the body and the footer are not counted.