fix(#936): updates discord links. (#937)

* discord link updated to working one on home page

* reverted yarn.lock file

* updated to medusajs url

www/docs/docusaurus.config.js

@@ -91,7 +91,7 @@ module.exports = {
             },
             {
               label: "Discord",
-              href: "https://discord.gg/H6naACAK",
+              href: "https://discord.gg/medusajs",
             },
             {
               label: "Twitter",