lib: improve spelling and grammar in comment

PR-URL: https://github.com/nodejs/node/pull/31026
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>

lib/events.js

@@ -145,8 +145,8 @@ EventEmitter.init = function(opts) {
     }
     this[kCapture] = Boolean(opts.captureRejections);
   } else {
-    // Assigning it directly a prototype lookup, as it slighly expensive
-    // and it sits in a very sensitive hot path.
+    // Assigning the kCapture property directly saves an expensive
+    // prototype lookup in a very sensitive hot path.
     this[kCapture] = EventEmitter.prototype[kCapture];
   }
 };