docs: Clear up confusion around where to register proxy services

docs/content/proxy-service/0.installation.md

@@ -26,7 +26,7 @@ export const [registerMathService, getMathService] = defineProxyService(
 ```ts [background.ts]
 import { registerMathService } from './MathService';
 
-// 2. As soon as possible, register it in the background script
+// 2. Register the service at the beginning of the background script
 registerMathService();
 ```
 
@@ -135,7 +135,7 @@ registerTodosRepo(db);
 
 ::
 
-You need to call `register` synchronously at the top level of the background script to avoid race conditions between registering and accessing the service for the first time.
+You need to call `register` synchronously at the beginning of the background script to avoid race conditions between registering and accessing the service for the first time.
 
 ::alert
 Here, even though `openDB` returns a promise, we're not awaiting the promise until executing the functions inside the service.