[docs] Remove @ts-ignore usage

Author: eps1lon

docs/src/pages/components/grid/InteractiveGrid.js

@@ -7,9 +7,6 @@ import RadioGroup from '@material-ui/core/RadioGroup';
 import Radio from '@material-ui/core/Radio';
 import Paper from '@material-ui/core/Paper';
 import { makeStyles } from '@material-ui/core/styles';
-// We don't have a typescript version of MarkdownElement
-// tslint:disable-next-line: ban-ts-ignore
-// @ts-ignore
 import MarkdownElement from 'docs/src/modules/components/MarkdownElement';
 
 const useStyles = makeStyles(theme => ({

docs/src/pages/components/grid/InteractiveGrid.tsx

@@ -7,9 +7,6 @@ import RadioGroup from '@material-ui/core/RadioGroup';
 import Radio from '@material-ui/core/Radio';
 import Paper from '@material-ui/core/Paper';
 import { makeStyles, createStyles, Theme } from '@material-ui/core/styles';
-// We don't have a typescript version of MarkdownElement
-// tslint:disable-next-line: ban-ts-ignore
-// @ts-ignore
 import MarkdownElement from 'docs/src/modules/components/MarkdownElement';
 
 const useStyles = makeStyles((theme: Theme) =>

docs/types/docs.d.ts

@@ -0,0 +1,14 @@
+declare module 'docs/src/modules/components/MarkdownElement' {
+  import React from 'react';
+  import { StyledComponentProps } from '@material-ui/core/styles';
+
+  type ClassKey = 'root';
+  export interface Props extends StyledComponentProps<ClassKey> {
+    className?: string;
+    /**
+     * text in markdown
+     */
+    text: string;
+  }
+  export default function MarkdownElement(props: Props): React.ReactElement;
+}