GO_DEPENDENCY_LABEL_${pipeline name} environment variable description is incorrect

[jseparovic]

It's not clear in the docs that the GO_DEPENDENCY_LABEL_ suffix should be the upstream pipeline's "Material Name". This name should be converted to uppercase with hyphens converted to underscores.

Eg:
The Pipeline Label for an Upstream Pipeline with "Material Name" = "upstream_services-frontend"

Would be available as the environment variable:
${GO_DEPENDENCY_LABEL_UPSTREAM_SERVICES_FRONTEND}

[ankitsri11]

@jseparovic thank you for pointing it out. I've raised a PR: #261 for an update.

Closing this issue out.