LibWeb: Add comments and missing items of various IDL files

Author: https://github.com/bplaat
Commit: 169d24ae2e
Pull-request: https://github.com/SerenityOS/serenity/pull/21588

Userland/Libraries/LibWeb/UserTiming/PerformanceMeasure.idl

@@ -1,10 +1,12 @@
 #import <PerformanceTimeline/PerformanceEntry.idl>
 
+// https://w3c.github.io/user-timing/#performancemeasure
 [Exposed=(Window,Worker)]
 interface PerformanceMeasure : PerformanceEntry {
     readonly attribute any detail;
 };
 
+// https://w3c.github.io/user-timing/#extensions-performance-interface
 dictionary PerformanceMeasureOptions {
     any detail;
     (DOMString or DOMHighResTimeStamp) start;