Migration page from "old" notifiers to "new" notifiers #4375

Job	Run time
build (stable, examples/counter)	1m 22s
build (stable, examples/marvel)	1m 14s
build (stable, examples/pub)	1m 9s
build (stable, examples/random_number)	1m 7s
build (stable, examples/stackoverflow)	1m 23s
build (stable, examples/todos)	1m 7s
build (stable, packages/riverpod)	2m 34s
build (stable, packages/riverpod/example)	1m 21s
build (stable, packages/flutter_riverpod)	1m 40s
build (stable, packages/flutter_riverpod/example)	1m 7s
build (stable, packages/hooks_riverpod)	1m 20s
build (stable, packages/hooks_riverpod/example)	1m 18s
build (stable, packages/riverpod_annotation)	53s
build (stable, packages/riverpod_generator)	1m 29s
build (stable, packages/riverpod_generator/integration/build_yaml)	2m 12s
build (stable, website)	1m 18s
build (master, examples/counter)	1m 35s
build (master, examples/marvel)	1m 29s
build (master, examples/pub)	1m 32s
build (master, examples/random_number)	1m 26s
build (master, examples/stackoverflow)	2m 1s
build (master, examples/todos)	1m 41s
build (master, packages/riverpod)	3m 4s
build (master, packages/riverpod/example)	1m 18s
build (master, packages/flutter_riverpod)	1m 49s
build (master, packages/flutter_riverpod/example)	1m 28s
build (master, packages/hooks_riverpod)	1m 50s
build (master, packages/hooks_riverpod/example)	1m 27s
build (master, packages/riverpod_annotation)	1m 22s
build (master, packages/riverpod_generator)	2m 12s
build (master, packages/riverpod_generator/integration/build_yaml)	2m 24s
build (master, website)	2m 4s
	51m 16s

Provide feedback