[Doc] Fix some typos

lib/cocoapods/installer/file_references_installer.rb

@@ -155,7 +155,7 @@ module Pod
       #         The key of the group of the Pods project.
       #
       # @param  [Bool] reflect_file_system_structure_for_development
-      #         Wether organizing the a local pod's files in subgroups inside
+      #         Whether organizing a local pod's files in subgroups inside
       #         the pod's group is allowed.
       #
       # @return [void]

lib/cocoapods/project.rb

@@ -171,7 +171,7 @@ module Pod
     #         The group for the new file reference.
     #
     # @param  [Bool] reflect_file_system_structure
-    #         Wether group structure should reflect the file system structure.
+    #         Whether group structure should reflect the file system structure.
     #         If yes, where needed, intermediate groups are created, similar to
     #         how mkdir -p operates.
     #