added common heading styles

src/App.tsx

@@ -1,10 +1,9 @@
 import React from 'react';
-import styles from './App.module.scss';
+import './App.scss';
 
 function App() {
   return (
     <div>
-
     </div>
   );
 }

src/common/styles/global.scss

@@ -7,4 +7,21 @@
     margin: 0;
     box-sizing: border-box;
     font-size: 62.5%;
+}
+
+header,
+h1,
+h2,
+h3,
+h4,
+h5,
+h6 {
+    font-weight: 700;
+    margin: 0;
+    color: var(--heading-color);
+    font-size: 2rem;
+}
+
+.taskText {
+    font-size: 1.5rem;
 }