docs: clarify Firecrawl limitations

README.md

@@ -87,6 +87,10 @@ Tool examples:
 }
 ```
 
+Notes:
+- Firecrawl self-hosted providers may omit `apiKey` when `baseUrl` is set.
+- Firecrawl does not support generic `highlights`; use Firecrawl `formats` such as `markdown`, `summary`, and `images` instead.
+
 Run `web-search-config` inside Pi to add or edit Tavily, Exa, and Firecrawl providers interactively.
 
 ## Development