refactor(commands): separate commands and its core into two folders (#32)

- I think it would be better if one for commands only, one for the spec
handling core logic so people won't be confused by the core logic inside
the commands folder (cleaner I guess)
- Regen docs

commands/ops/tkn.go

@@ -1,14 +1,14 @@
 package ops
 
 import (
-	"github.com/versenilvis/iris/commands/core"
+	"github.com/versenilvis/iris/spec"
 )
 
 func init() {
-	core.Register(&core.Spec{
+	spec.Register(&spec.Spec{
 		Name:        "tkn",
 		Description: "CLI for tekton pipelines",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "tkb", Description: "Manage Tekton Bundles"},
 			{Name: "list", Description: "List and print a Tekton bundle's contents"},
 			{Name: "push", Description: "Create or replace a Tekton bundle"},
@@ -50,7 +50,7 @@ func init() {
 			{Name: "version", Description: "Prints version information"},
 			{Name: "help", Description: "Help about any command"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "--allow-missing-template-keys", Description: "A directory to cache Tekton bundles in"},
 			{Name: "--no-cache", Description: "A Bearer token to authenticate against the repository"},
 			{Name: "--remote-password", Description: "If set to true, skips TLS check when connecting to the registry"},