Fixed an error starting the project

The following occurred on `yarn start`:
TypeError: Cannot assign to read only property 'jsx' of object '#<Object>'
See: facebook/create-react-app#10110 (comment)

Author: ZeeCoder

.gitignore

@@ -17,7 +17,7 @@
 .env.development.local
 .env.test.local
 .env.production.local
-
 npm-debug.log*
 yarn-debug.log*
 yarn-error.log*
+.eslintcache

package.json

@@ -12,7 +12,7 @@
     "@types/react-dom": "^16.9.8",
     "react": "^17.0.1",
     "react-dom": "^17.0.1",
-    "react-scripts": "4.0.0",
+    "react-scripts": "^4.0.0",
     "typescript": "^4.0.3",
     "web-vitals": "^0.2.4"
   },

tsconfig.json

@@ -18,7 +18,7 @@
     "resolveJsonModule": true,
     "isolatedModules": true,
     "noEmit": true,
-    "jsx": "react"
+    "jsx": "react-jsx"
   },
   "include": [
     "src"