Fix type in README.md (#151)

Author: timothyjellison

README.md

@@ -12,7 +12,7 @@
 Mock your future API or extend the existing API with realistic data from [faker.js](https://github.com/Marak/faker.js). **No coding required**.
 All you need is to write [GraphQL SDL](https://alligator.io/graphql/graphql-sdl/). Don't worry, we will provide you with examples in our SDL editor.
 
-In the GIF bellow we add fields to types inside real GitHub API and you can make queries from GraphiQL, Apollo, Relay, etc. and receive **real data mixed with mock data.**
+In the GIF below we add fields to types inside real GitHub API and you can make queries from GraphiQL, Apollo, Relay, etc. and receive **real data mixed with mock data.**
 ![demo-gif](./docs/demo.gif)
 
 ## How does it work?