Fix typo in chessboard introduction and about docs (#851)

* Fix typo in introduction and about docs

* Fix typo in exercise introduction

Author: aybarsnazlica

concepts/ranges/about.md

@@ -14,7 +14,7 @@ The reason for having two range operators is to create ranges that are inclusive
 
 ~~~~exercism/note
 When creating a range in Swift using the range operators `...` or `..<`, and wanting to call a method on the range, you need to wrap the range in parentheses.
-This is because the otherwise will the method be called on the 2nd argument of the range operator.
+This is because otherwise the method will be called on the 2nd argument of the range operator.
 
 ```swift
 (1...5).contains(3) // Returns true

concepts/ranges/introduction.md

@@ -14,7 +14,7 @@ The reason for having two range operators is to create ranges that are inclusive
 
 ~~~~exercism/note
 When creating a range in Swift using the range operators `...` or `..<`, and wanting to call a method on the range, you need to wrap the range in parentheses.
-This is because the otherwise will the method be called on the 2nd argument of the range operator.
+This is because otherwise the method will be called on the 2nd argument of the range operator.
 
 ```swift
 (1...5).contains(3) // Returns true

exercises/concept/chessboard/.docs/introduction.md

@@ -14,7 +14,7 @@ The reason for having two range operators is to create ranges that are inclusive
 
 ~~~~exercism/note
 When creating a range in Swift using the range operators `...` or `..<`, and wanting to call a method on the range, you need to wrap the range in parentheses.
-This is because the otherwise will the method be called on the 2nd argument of the range operator.
+This is because otherwise the method will be called on the 2nd argument of the range operator.
 
 ```swift
 (1...5).contains(3) // Returns true