README, small edit for usage specificity.

README.md

@@ -10,7 +10,9 @@ for sungazing, or as a reminder to go and find a campsite before it gets dark.
 
 ## Usage
 
-() sections are required. [] sections are optional. | denotes multiple options.
+`()` sections are required.
+`[]` sections are optional.
+`|` separates multiple options in a group.
 
 ```console
 sunset-timer (-l LAT:LONG | -t HH24:MI) (-m MINUTES) [-h]