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/view/glow.go

@@ -1,19 +1,19 @@
 package view
 
 import (
-	"github.com/versenilvis/iris/commands/core"
+	"github.com/versenilvis/iris/spec"
 )
 
 func init() {
-	core.Register(&core.Spec{
+	spec.Register(&spec.Spec{
 		Name:        "glow",
 		Description: "Render markdown on the CLI, with pizzazz!",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "config", Description: "Edit the glow config file"},
 			{Name: "help", Description: "Help about any command"},
 			{Name: "stash", Description: "Manage your stash of markdown files"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "-a", Description: "Show system files and directories (TUI-mode only)"},
 			{Name: "--config", Description: "Config file"},
 			{Name: "-h", Description: "Help for glow"},