feat(table): add cell component

This adds a cell component which provides basic styling for cell content.

packages/index.ts

@@ -1,3 +1,3 @@
 export { Badge } from "./badge";
 export { BadgeButton } from "./badge";
-export { Column, Table } from "./table";
+export { Column, Table, Cell } from "./table";

packages/table/components/Cell.tsx

@@ -0,0 +1,7 @@
+import styled from "react-emotion";
+
+export default styled("div")`
+  height: 100%;
+  box-sizing: border-box;
+  padding: 7px;
+`;

packages/table/index.ts

@@ -1,2 +1,3 @@
 export { default as Table } from "./components/Table";
 export { default as Column } from "./components/Column";
+export { default as Cell } from "./components/Cell";