fix(docs): Standardize URLs with no trailing slash

Previously, a trailing slash would be appended to all URLs when accessed
directly, but not when accessed via menus and links.

This Docusaurus configuration option keeps the URLs consistent by never
appending a trailing slash.

https://docusaurus.io/docs/api/docusaurus-config#trailing-slash

docs/docusaurus.config.js

@@ -6,6 +6,7 @@ module.exports = {
   url: "https://zmk.dev",
   baseUrl: "/",
   favicon: "img/favicon.ico",
+  trailingSlash: "false",
   organizationName: "zmkfirmware", // Usually your GitHub org/user name.
   projectName: "zmk", // Usually your repo name.
   plugins: [