Update docs/toolhive/guides-registry/intro.mdx

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: rdimitrov

docs/toolhive/guides-registry/intro.mdx

@@ -29,7 +29,7 @@ exposes it through a standardized API. When you start the server, it:
 1. Loads configuration from a YAML file
 2. Runs database migrations automatically
 3. Immediately fetches registry data from the configured sources
-4. Starts background sync coordinator for automatic updates (for synced sources)
+4. Starts a background sync coordinator for automatic updates (for synced sources)
 5. Serves MCP Registry API endpoints on the configured address
 
 ```mermaid