docs(all): update contributing guide
1. Sign one of the contributor license agreements below.
1. [Install Go](https://golang.org/doc/install).
-1. Get the package:
+1. Clone the repo:
- `go get -d github.com/GoogleCloudPlatform/golang-samples`
+ `git clone https://github.com/GoogleCloudPlatform/golang-samples.git`
1. Change into the checked out source:
- `cd $(go env GOPATH)/src/github.com/GoogleCloudPlatform/golang-samples`
+ `cd golang-samples`
1. Fork the repo.
1. Set your fork as a remote:
- `git remote add fork git@github.com:GITHUB_USERNAME/golang-samples.git`
-1. Make changes (see [Formatting](#formatting) and [Style](#style)), commit to
- your fork. Commit messages should follow the
- [Go project style](https://github.com/golang/go/wiki/CommitMessage) (e.g.
- `functions: add gophers codelab`).
+ `git remote add fork https://github.com/GITHUB_USERNAME/golang-samples.git`
+1. Make changes (see [Formatting](#formatting) and [Style](#style)) and commit
+ to your fork. Initial commit messages should follow the
+ [Conventional Commits](https://www.conventionalcommits.org/) style (e.g.
+ `feat(functions): add gophers codelab`).
1. Send a pull request with your changes.
1. A maintainer will review the pull request and make comments. Prefer adding
additional commits over ammending and force-pushing since it can be difficult
