contrib: Fix typo

Author: claremacrae

contributing/Testing/About Testing.md

@@ -23,7 +23,7 @@ Testing dates and times:
 
 - [[How do I use Moment in tests]] - how to test date and time values
 - [[Simulating Dates and Times]] - examples of how to use fixed dates and times in tests
-- [[Testing and Time Zones]] - how test in different time zones (with difficulty)
+- [[Testing and Time Zones]] - how to test in different time zones (with difficulty)
 
 Testing code that uses Obsidian API: