Clarify JSON configuration file usage in docs

Updated recommendation for configuration file format.

Author: penalosa

src/content/docs/workers/wrangler/configuration.mdx

@@ -18,7 +18,7 @@ Wrangler optionally uses a configuration file to customize the development and d
 
 As of Wrangler v3.91.0 Wrangler supports both JSON (`wrangler.json` or `wrangler.jsonc`) and TOML (`wrangler.toml`) for its configuration file. Prior to that version, only `wrangler.toml` was supported.
 
-Cloudflare recommends using `wrangler.jsonc` for new projects.
+Cloudflare recommends using `wrangler.jsonc` for new projects, and some newer Wrangler features will only be available to projects using a JSON config file.
 
 The format of Wrangler's configuration file is exactly the same across both languages, only the syntax differs.