add example for "git log -- path"

Signed-off-by: Junjie Yuan <[email protected]>

Author: junjieyuan

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

@@ -262,7 +262,12 @@ $ git log -S function_name
 
 The last really useful option to pass to `git log` as a filter is a path.
 If you specify a directory or file name, you can limit the log output to commits that introduced a change to those files.
-This is always the last option and is generally preceded by double dashes (`--`) to separate the paths from the options.
+This is always the last option and is generally preceded by double dashes (`--`) to separate the paths from the options:
+
+[source,console]
+----
+$ git log -- path/to/file
+----
 
 In <<limit_options>> we'll list these and a few other common options for your reference.