update README link for lib/apis godoc
update README link for lib/apis godoc

During migration of api and apiv2 into apis/v1 and apisv2 (see
ff2d5f09ce8b11712e6848e7ddb6dc415ba8bde4) the README was was not updated
to reflect the changes.

Signed-off-by: derek mcquay <e1c79a582b6629e6b39e9679f4bb964d25db4aa8@tigera.io>

projectcalico/libcalico-go,insequent/libcalico-go,insequent/libcalico-go,projectcalico/libcalico-go