chore: address comments

Co-Authored-By: Daniel Dyla <dyladan@users.noreply.github.com>

packages/opentelemetry-plugin-express/README.md

@@ -47,7 +47,7 @@ See [examples/express](/~https://github.com/open-telemetry/opentelemetry-js/tree/m
 
 ### Caveats
 
-Because of the way express works, it's hard to correctly compute the time took by asynchronous code to complete. For this reason the time you'll see reported for asynchronous middlewares and request handlers will **not** represent the time it really took.
+Because of the way express works, it's hard to correctly compute the time taken by asynchronous middlewares and request handlers. For this reason, the time you'll see reported for asynchronous middlewares and request handlers will only represent the synchronous execution time, and **not** any asynchronous work.
 
 ### Express Plugin Options