Update 'responsive size mapping' example - page ID
Update 'responsive size mapping' example - page ID

Bump the page ID so the page ordering in the list of examples is
consistent.

Prior to this, there were two pages in the list with PID 101, so the
ordering of those two examples was random.

prebid/prebid.github.io,prebid/prebid.github.io,sonobi/prebid.github.io,prebid/prebid.github.io,sonobi/prebid.github.io,sonobi/prebid.github.io