Add search config (#41)

Algolia was nice enough to crawl our site! 🎉 

Fixes #26

So now update the config with the relevant information.

Note we actually already have a search navbar item, but since we didn't
configure search it wasn't rendered previously)

docusaurus.config.js

@@ -256,6 +256,12 @@ const config = {
       ],
       copyright: `Copyright © ${new Date().getFullYear()} Pants project contributors. Built with Docusaurus.`,
     },
+    algolia: {
+      appId: "QD9KY1TRVK",
+      apiKey: "633f6891a9c1a7db671ce285a5a63819",
+      indexName: "pantsbuild",
+      contextualSearch: true,
+    },
     prism: {
       additionalLanguages: [
         "bash",