* Add docs about local provider to CONTRIBUTING
Add docs about using a local provider with Terraform to CONTRIBUTING.md.
I couldn't find any prescriptive docs for this, so let's make them. Let me know if a different method is preferred (such as `.terraformrc`), this seemed like the best way from my brief search.
Upstreamed https://github.com/hashicorp/terraform-website/pull/474 as well to help improve the central Terraform docs on this subject.
* Update CONTRIBUTING.md (#2086)
I've seen questions about how to vendor come up from new members of our team and from the community in some OSS issues. Let's make our tribal knowledge a documented process!
I largely stole these from github.com/terraform-providers/terraform-provider-aws, but with a few changes:
* I called out how we assign users to issues, to make it more transparent to users.
* I added a "success story" issue that will be automatically closed and labeled, to keep track of those stories.
* I added a `[issue-type:TYPE]` string to each, so hashibot can detect and act on them.