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/python/jupyter.go

@@ -1,14 +1,14 @@
 package python
 
 import (
-	"github.com/versenilvis/iris/commands/core"
+	"github.com/versenilvis/iris/spec"
 )
 
 func init() {
-	core.Register(&core.Spec{
+	spec.Register(&spec.Spec{
 		Name:        "jupyter",
 		Description: "Set log level to logging.DEBUG (maximize logging output)",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "bundlerextension", Description: "Work with Jupyter bundler extensions"},
 			{Name: "enable", Description: "Enable a bundler extension"},
 			{Name: "disable", Description: "Disable a bundler extension"},
@@ -27,7 +27,7 @@ func init() {
 			{Name: "troubleshoot", Description: "Log for troubleshooting"},
 			{Name: "trust", Description: "Manage trust"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "--debug", Description: "Set log level to logging.DEBUG (maximize logging output)"},
 			{Name: "-h", Description: "Show this message"},
 			{Name: "--log-level", Description: "Set the log level by value or name"},