all: fix doc on type Field to not refer to old XML API docs
all: fix doc on type Field to not refer to old XML API docs

Change-Id: Ided9e588f6d847c2cf12fd8b3c07dc98a63a0cb8
Reviewed-on: https://code-review.googlesource.com/c/google-api-go-client/+/47850
Reviewed-by: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>
Reviewed-by: Frank Natividad <52e924866916bede4f49dda05c657c45c4ff3b20@google.com>
Reviewed-by: Chris Cotter <b879ae7d4b52f11ce9f60d9854075eb8eebaf7a9@google.com>

googleapis/google-api-go-client,google/google-api-go-client,googleapis/google-api-go-client,google/google-api-go-client