add basic extension manager

packages/tiptap-core/src/ExtensionManager.ts

@@ -0,0 +1,34 @@
+import { keymap } from 'prosemirror-keymap'
+import { Editor } from './Editor'
+
+export default class ExtensionManager {
+
+  extensions: [any?]
+
+  constructor(extensions: any = [], editor: Editor) {
+    // extensions.forEach(extension => {
+    //   extension.bindEditor(editor)
+    //   extension.init()
+    // })
+    this.extensions = extensions
+  }
+
+  get nodes() {
+    return this.extensions
+      .filter(extension => extension.type === 'node')
+      .reduce((nodes, { name, schema }) => ({
+        ...nodes,
+        [name]: schema,
+      }), {})
+  }
+
+  get marks() {
+    return this.extensions
+      .filter(extension => extension.type === 'mark')
+      .reduce((marks, { name, schema }) => ({
+        ...marks,
+        [name]: schema,
+      }), {})
+  }
+
+}