fix: allow root path in base path type

Co-authored-by: Y.D.X. <[email protected]>

Author: 3w36zj6

website/src/metadata.ts

@@ -17,4 +17,4 @@ export const discordServerUrl = "https://discord.gg/9xF7k4aAuH";
 /** The origin URL of the deployed site, used for metadata. Note that the base path should not be included. */
 export const originUrl = "https://typst-jp.github.io/";
 /** The base public path for deployment. This must match the value used in typst-docs. */
-export const basePath: `/${string}/` = "/docs/";
+export const basePath: "/" | `/${string}/` = "/docs/";