Change PluralRules & RelativeTimeFormat spec URLs (#5545)
Change PluralRules & RelativeTimeFormat spec URLs (#5545)

This change switches the spec URLs for Intl.PluralRules and
Intl.RelativeTimeFormat to the fragment IDs for the top-level spec
sections for those objects, rather the fragment IDs for the subsections
for their constructors.
mdn/browser-compat-data,chrisdavidmills/browser-compat-data,mdn/browser-compat-data,chrisdavidmills/browser-compat-data