minor typo correction (pointfreeco#601)

Author: heckj

Documentation/Available-Snapshot-Strategies.md

@@ -1,6 +1,6 @@
 # Available Snapshot Strategies
 
-SnapshotTesting comes with a wide variety of snapshot strategies for a varienty of platforms. To extend these strategies or define your own, see [Defining Custom Snapshot Strategies](Defining-Custom-Snapshot-Strategies.md).
+SnapshotTesting comes with a wide variety of snapshot strategies for a variety of platforms. To extend these strategies or define your own, see [Defining Custom Snapshot Strategies](Defining-Custom-Snapshot-Strategies.md).
 
 If you'd like to submit your own custom strategy, see [Contributing](../CONTRIBUTING.md).