Merged master

.gitignore

@@ -137,3 +137,4 @@ dist
 npm-debug.log*
 yarn-debug.log*
 yarn-error.log*
+yarn.lock

README.md

@@ -40,5 +40,5 @@ yarn run
 ## Useful resources
 
 [react calendar app](https://codesandbox.io/s/kkyvoj97pv?from-embed=&file=/src/index.js)
-[codesandbox, utile per vedere altri progetti creati con framework)(https://codesandbox.io/)
+[codesandbox, utile per vedere altri progetti creati con framework](https://codesandbox.io/)
 [awesome css list](https://github.com/awesome-css-group/awesome-css)

src/react-app-env.d.ts

+/// <reference types="react-scripts" />