feat: use div as default component (#48)

* Change Cell to use div

BREAKING CHANGE: Anything relying on the Cell component rendering a `section` tag will need to be update to expect `div`s.

Author: jvgomg

lib/Cell.js

@@ -1,7 +1,7 @@
 import styled from "styled-components";
 import PropTypes from "prop-types";
 
-const Cell = styled.section`
+const Cell = styled.div`
   height: 100%;
   min-width: 0;
   grid-column-end: ${({ width = 1 }) => `span ${width}`};

lib/__tests__/__snapshots__/Cell.test.js.snap

@@ -23,7 +23,7 @@ exports[`<Cell/> 'middle' prop vertically aligns contents 1`] = `
   justify-self: stretch;
 }
 
-<section
+<div
   className="c0"
 />
 `;
@@ -36,7 +36,7 @@ exports[`<Cell/> matches snapshot with default args 1`] = `
   grid-row-end: span 1;
 }
 
-<section
+<div
   className="c0"
 />
 `;