Merge pull request #552 from YueLinHo/fix_i551

Fix issue #551: Missing backtick(`)

Author: ben

book/02-git-basics/sections/viewing-history.asc

@@ -156,7 +156,7 @@ ca82a6d - Scott Chacon, 6 years ago : changed the version number
 a11bef0 - Scott Chacon, 6 years ago : first commit
 ----
 
-<<pretty_format>> lists some of the more useful options that format takes.
+<<pretty_format>> lists some of the more useful options that `format` takes.
 
 [[pretty_format]]
 .Useful options for `git log --pretty=format`