feat: fix typescript typing, and add in an import

fix HospitalRun#664

src/components/Layout/Column.tsx

@@ -6,7 +6,7 @@ interface Props {
    * HTML element to be used for the component
    * @default <div>
    */
-  as?: React.ElementType
+  as?: keyof JSX.IntrinsicElements
   /**
    * The number of columns to span on extra large devices (≥ 1200px)
    */

src/components/Layout/Container.tsx

@@ -6,7 +6,7 @@ interface Props {
    * A custom element to be used for the component
    * @default <div>
    */
-  as?: React.ElementType
+  as?: keyof JSX.IntrinsicElements // As extends React.ElementType // '"symbol" | undefined'
   /**
    * Allow the Container to fill all of its available horizontal space
    * @default false

src/components/Layout/Row.tsx

@@ -1,12 +1,13 @@
-import React, { CSSProperties } from 'react'
+import { CSSProperties } from 'react'
+import * as React from 'react'
 import BootstrapRow from 'react-bootstrap/Row'
 
 interface Props {
   /**
    * HTML element to be used for the component
    * @default <div>
    */
-  as?: React.ElementType
+  as?: keyof JSX.IntrinsicElements // React.ElementType
   /**
    * Removes the gutter spacing between `Columns` as well as any added negative margins.
    * @default false

stories/typography.stories.tsx

@@ -1,4 +1,5 @@
 import { storiesOf } from '@storybook/react'
+import * as React from 'react'
 
 import { Typography } from '../src'