feat: init the editor of workbench

Author: wewoor

src/workbench/editor/editor.scss

@@ -0,0 +1,9 @@
+@import '@/style/const.scss';
+
+.#{$prefix}-editor {
+    position: absolute;
+    width: 100%;
+    height: 100%;
+    // TODO temp style, just for development
+    background-color: #1e1e1e;
+}

src/workbench/editor/index.tsx

@@ -0,0 +1,15 @@
+import * as React from 'react';
+
+import { prefixClaName } from '@/common/className';
+
+import './editor.scss';
+
+export const Editor: React.FunctionComponent = function() {
+    return (
+        <div className={prefixClaName('editor')}>
+            Editor
+        </div>
+    );
+};
+
+export default Editor;