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/rust/taplo.go

@@ -1,14 +1,14 @@
 package rust
 
 import (
-	"github.com/versenilvis/iris/commands/core"
+	"github.com/versenilvis/iris/spec"
 )
 
 func init() {
-	core.Register(&core.Spec{
+	spec.Register(&spec.Spec{
 		Name:        "taplo",
 		Description: "Set color values for the output",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "config", Description: "Operations with the Taplo config file"},
 			{Name: "default", Description: "Print the default `.taplo.toml` configuration file"},
 			{Name: "help", Description: "Print this message or the help of the given subcommand(s)"},
@@ -22,7 +22,7 @@ func init() {
 			{Name: "stdio", Description: "Run the language server over the standard input and output"},
 			{Name: "tcp", Description: "Run the language server and listen on a TCP address"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "--colors", Description: "Set color values for the output"},
 			{Name: "--verbose", Description: "Enable verbose logging format"},
 			{Name: "--log-spans", Description: "Enable logging spans"},