Update static-type-checking.md

The document did not specify where to edit `babel` config.

It is confused for beginner

Author: tranvansang

content/docs/static-type-checking.md

@@ -24,7 +24,7 @@ yarn add --dev babel-preset-flow
 npm install --save-dev babel-preset-flow
 ```
 
-Then add `flow` to your Babel presets config.
+Then add `flow` to your Babel presets config in`.babelrc`.
 
 ```json
 {
@@ -57,4 +57,4 @@ You can learn more about using TypeScript with React [here](https://github.com/M
 create-react-app my-app --scripts-version=react-scripts-ts
 ```
 
-You can also try [typescript-react-starter](https://github.com/Microsoft/TypeScript-React-Starter#typescript-react-starter).
+You can also try [typescript-react-starter](https://github.com/Microsoft/TypeScript-React-Starter#typescript-react-starter).