docs: fix typo in README (#689)

Author: fischerscode

packages/dart/README.md

@@ -249,7 +249,7 @@ This method returns an `Future` that either resolves in an error (equivalent of
 
 Choosing between `query()` and `find()` comes down to personal preference. Both methods can be used for querying a `ParseQuery`, just the output method differs.
 
-Similar to `find()` the `QueryBuilder` also has a function called `Future<T>? first()`. Just like `find()` `first()` is just a convenience method that makes querying the first object satisfying the query simpler. `first()` returns an `Future`, that resoles in an error or the first object matching the query. In case no object satisfies the query, the result will be `null`.
+Similar to `find()` the `QueryBuilder` also has a function called `Future<T?> first()`. Just like `find()` `first()` is just a convenience method that makes querying the first object satisfying the query simpler. `first()` returns an `Future`, that resoles in an error or the first object matching the query. In case no object satisfies the query, the result will be `null`.
 
 ## Complex queries
 You can create complex queries to really put your database to the test:

packages/flutter/README.md

@@ -279,7 +279,7 @@ This method returns an `Future` that either resolves in an error (equivalent of
 
 Choosing between `query()` and `find()` comes down to personal preference. Both methods can be used for querying a `ParseQuery`, just the output method differs.
 
-Similar to `find()` the `QueryBuilder` also has a function called `Future<T>? first()`. Just like `find()` `first()` is just a convenience method that makes querying the first object satisfying the query simpler. `first()` returns an `Future`, that resoles in an error or the first object matching the query. In case no object satisfies the query, the result will be `null`.
+Similar to `find()` the `QueryBuilder` also has a function called `Future<T?> first()`. Just like `find()` `first()` is just a convenience method that makes querying the first object satisfying the query simpler. `first()` returns an `Future`, that resoles in an error or the first object matching the query. In case no object satisfies the query, the result will be `null`.
 
 ## Complex queries
 You can create complex queries to really put your database to the test: