Fix changelog for 6.2.0-alpha.1 (#397)

* Fix changelog

* Fix docs typo

Author: jmkiley

platform/darwin/src/MGLObserver.h

@@ -26,7 +26,7 @@ MGL_EXPORT
 #pragma mark -
 
 /**
- Protocol that yypes that wish to support subscriptions for events should conform
+ Protocol that types that wish to support subscriptions for events should conform
  to.
  */
 MGL_EXPORT

platform/ios/CHANGELOG.md

@@ -2,7 +2,7 @@
 
 Mapbox welcomes participation and contributions from everyone. Please read [CONTRIBUTING.md](../../CONTRIBUTING.md) to get started.
 
-# 6.2.0
+## 6.2.0
 
 ### ✨ New features