Relation to the `PerformanceEntry` interface missing

[shubhamg13]

There should be explicit block mentioning the reklation with like one from Navigation Timing 3.1. Relation to the PerformanceEntry interface

[shubhamg13]

cc: @xiaochengh

[mmocny]

Nit: I think the main goal here is that Resource Timing is missing definitions for things like name or entryType as defined by the base PerformanceEntry.

I think the specific proposal of adding a "Relation to the PerformanceEntry interface" section of the spec is one mechanism-- consistent with Navigation Timing-- but many other specs just define these in the interface section.

Either way, thanks for noticing!

[shubhamg13]

Thanks for review. I will prepare PR soon.