Added a description for the "Classic" editor #2832 (#2919)

* Added a description for the "Classic" editor #2832

* Removed undefined "focus" - resolves broken unit test

* 1. removed variable usage as suggested by @aduth
2. Updated description #2832

* Adjusted description of classic text block

blocks/library/freeform/old-editor.js

@@ -5,6 +5,12 @@ import { Component } from '@wordpress/element';
 import { __ } from '@wordpress/i18n';
 import { keycodes } from '@wordpress/utils';
 
+/**
+ * Internal dependencies
+ */
+import InspectorControls from '../../inspector-controls';
+import BlockDescription from '../../block-description';
+
 const { BACKSPACE, DELETE } = keycodes;
 
 function isTmceEmpty( editor ) {
@@ -160,6 +166,11 @@ export default class OldEditor extends Component {
 		const { id } = this.props;
 
 		return [
+			<InspectorControls key="inspector">
+				<BlockDescription>
+					<p>{ __( 'The classic editor, in block form.' ) }</p>
+				</BlockDescription>
+			</InspectorControls>,
 			<div
 				key="toolbar"
 				id={ id + '-toolbar' }