doc/go1.18: list new net/netip and net functions and methods
doc/go1.18: list new net/netip and net functions and methods

For #46518
For #47694

Change-Id: I4848556674baf85ceec350645d9eddcd83f1b2e0
Reviewed-on: https://go-review.googlesource.com/c/go/+/373834
Trust: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>
Trust: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>

nawawi/go,CAFxX/go,nawawi/go,golang/go,nawawi/go,CAFxX/go,cloudflare/go,golang/go,nawawi/go,cloudflare/go,nawawi/go,CAFxX/go,cloudflare/go,cloudflare/go,CAFxX/go,CAFxX/go,cloudflare/go,cloudflare/go,golang/go,CAFxX/go,CAFxX/go,golang/go,golang/go,cloudflare/go,cloudflare/go,nawawi/go,nawawi/go,golang/go,CAFxX/go,nawawi/go,golang/go,golang/go