Rename `tk` binary to `gotk`

.github/workflows/docs.yaml

.github/workflows/e2e.yaml

.goreleaser.yml

Makefile

README.md

cmd/gotk/bootstrap.go

cmd/gotk/bootstrap_github.go

cmd/gotk/bootstrap_gitlab.go

cmd/gotk/check.go

cmd/gotk/completion.go

cmd/gotk/create.go

cmd/gotk/create_helmrelease.go

cmd/gotk/create_kustomization.go

cmd/gotk/create_source.go

cmd/gotk/create_source_git.go

cmd/gotk/create_source_helm.go

cmd/gotk/delete.go

cmd/gotk/delete_helmrelease.go

cmd/gotk/delete_kustomization.go

cmd/gotk/delete_source.go