Add go generate mention to CONTRIBUTING.md (#2587)

Fixes: #2579.

CONTRIBUTING.md

@@ -44,9 +44,8 @@ are more sensitive, emailed to <opensource@google.com>.
 
   1. Go makes it very simple to ensure properly formatted code, so always run
      `go fmt` on your code before committing it. You should also run
-     [golint][] over your code. As noted in the [golint readme][], it's not
-     strictly necessary that your code be completely "lint-free", but this will
-     help you find common style issues.
+     [go vet][] over your code. this will help you find common style issues
+     within your code and will keep styling consistent within the project.
 
   1. Any significant changes should almost always be accompanied by tests. The
      project already has good test coverage, so look at some of the existing
@@ -59,18 +58,35 @@ are more sensitive, emailed to <opensource@google.com>.
      * `go test github.com/google/go-github/...`
      * `go vet github.com/google/go-github/...`
 
+   The `go generate ./...` command will update or generate certain files, and the 
+   resulting changes should be included in your pull request.
+
+   The `go test ./...` command will run tests inside your code. This will help you
+   spot places where code might be faulty before committing.
+
+   And finally, the `go vet ./...` command will check linting and styling over your 
+   code, keeping the project consistent formatting-wise.
+
+   In any case, it is always a good idea to read [official Go documentation][] when working 
+   on this project, as the definition of tools and commands of the Go programming 
+   language is described in further detail there.
+
   1. Do your best to have [well-formed commit messages][] for each change.
      This provides consistency throughout the project, and ensures that commit
      messages are able to be formatted properly by various git tools.
 
   1. Finally, push the commits to your fork and submit a [pull request][].
+     Before pushing commits, it is highly advised to check for generated files
+     that were either created or modified for the sake of your commit. Running
+     `go generate -x ./...` should return a log of modified generated files that should
+     be included alongside the manually written code in the commit.
      **NOTE:** Please do not use force-push on PRs in this repo, as it makes
      it more difficult for reviewers to see what has changed since the last
      code review.
 
+[official Go documentation]: https://pkg.go.dev/std
 [forking]: https://help.github.com/articles/fork-a-repo
-[golint]: https://github.com/golang/lint
-[golint readme]: https://github.com/golang/lint/blob/master/README.md
+[go vet]: https://pkg.go.dev/cmd/vet
 [gocov]: https://github.com/axw/gocov
 [gocov-html]: https://github.com/matm/gocov-html
 [well-formed commit messages]: http://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html
@@ -128,4 +144,5 @@ this][modified-comment].
 [rebase-comment]: https://github.com/google/go-github/pull/277#issuecomment-183035491
 [modified-comment]: https://github.com/google/go-github/pull/280#issuecomment-184859046
 
-**When creating a release, don't forget to update the `Version` constant in `github.go`.** This is used to send the version in the `User-Agent` header to identify clients to the GitHub API.
+**When creating a release, don't forget to update the `Version` constant in `github.go`.** This is used to 
+send the version in the `User-Agent` header to identify clients to the GitHub API.