v1.1.0: Exclude godoc examples by default (#4)

godoc examples (https://blog.golang.org/examples) depend on being able to write to stdout, which is in contradiction to the default forbidden pattern of fmt.Print*. To make this work nicely out of the box, we will skip checking godoc examples by default. This includes "whole file examples", in which an entire file is ignored because it has only a single Example* method.

This PR also allows the //permit directive to be ignored, allowing this linter to be controlled just using the standard //nolint directive from golangci lint.

This PR also adds a dependency on the launchdarkly/go-options option code generator, which isn't pinned in the repo. I may consider doing that at a later date.

Fixes #3