Add custom config table class for crawler (#104)

Creates "hook" class for Algolia crawler.

Updates crawler as such:

```
recordProps: {
  lvl1: "article h1",
  content: "article p, article li, article table.config-table td, article table.config-table th",
  lvl0: {
    selectors: ".menu > .menu__list > li > .menu__link--active",
    defaultValue: "Documentation",
  },
  lvl2: "article h2",
  lvl3: "article h3",
  lvl4: "article h4",
  lvl5: "article h5",
},
```

src/theme/ConfigTable/index.tsx

@@ -1,4 +1,3 @@
-import React from "react"
 import ReactMarkdown from "react-markdown"
 
 type Props = {
@@ -8,7 +7,7 @@ type Props = {
 
 export const ConfigTable = ({ rows, pick }: Props) => {
   return (
-    <table>
+    <table className="config-table">
       <thead>
         <tr>
           <th>Property</th>
@@ -32,4 +31,4 @@ export const ConfigTable = ({ rows, pick }: Props) => {
       </tbody>
     </table>
   )
-}
+}