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/multipass.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:        "multipass",
 		Description: "Displays help on commandline options",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "alias", Description: "Create an alias"},
 			{Name: "definition", Description: "Alias definition in the form <instance>:<command>"},
 			{Name: "aliases", Description: "List available aliases"},
@@ -41,7 +41,7 @@ func init() {
 			{Name: "unalias", Description: "Remove an alias"},
 			{Name: "version", Description: "Show version details"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "-h", Description: "Displays help on commandline options"},
 			{Name: "--help-all", Description: "Displays help including Qt specific options"},
 			{Name: "-v", Description: "Increase logging verbosity. Repeat the 'v' in the short"},