Refactored version directory names

3.0 and 2.0 do not work, there are multiple versions and anything with a period in it sucks from my point of view, v2 and v3 feel much better from a DX perspective.

datamodel/low/v3/document.go

@@ -0,0 +1,40 @@
+// Copyright 2022 Princess B33f Heavy Industries / Dave Shanley
+// SPDX-License-Identifier: MIT
+
+package v3
+
+import (
+	"github.com/pb33f/libopenapi/datamodel/low"
+	"github.com/pb33f/libopenapi/datamodel/low/base"
+	"github.com/pb33f/libopenapi/index"
+)
+
+type Document struct {
+	Version           low.ValueReference[string]
+	Info              low.NodeReference[*base.Info]
+	JsonSchemaDialect low.NodeReference[string]                                                     // 3.1
+	Webhooks          low.NodeReference[map[low.KeyReference[string]]low.ValueReference[*PathItem]] // 3.1
+	Servers           low.NodeReference[[]low.ValueReference[*Server]]
+	Paths             low.NodeReference[*Paths]
+	Components        low.NodeReference[*Components]
+	Security          low.NodeReference[*SecurityRequirement]
+	Tags              low.NodeReference[[]low.ValueReference[*base.Tag]]
+	ExternalDocs      low.NodeReference[*base.ExternalDoc]
+	Extensions        map[low.KeyReference[string]]low.ValueReference[any]
+	Index             *index.SpecIndex
+}
+
+//
+//func (d *Document) AddTag() *base.Tag {
+//	t := base.NewTag()
+//	//d.Tags.KeyNode
+//	t.Name.Value = "nice new tag"
+//
+//	dat, _ := yaml.Marshal(t)
+//	var inject yaml.Node
+//	_ = yaml.Unmarshal(dat, &inject)
+//
+//	d.Tags.ValueNode.Content = append(d.Tags.ValueNode.Content, inject.Content[0])
+//
+//	return t
+//}