move nodes and marks to a separate folder, add missing extensions

docs/src/docPages/api/nodes/text.md

@@ -0,0 +1,21 @@
+# Text
+**The `Text` extension is required**, at least if you want to work with text of any kind and that’s very likely. This extension is a little bit different, it doesn’t even render HTML. It’s plain text, that’s all.
+
+:::warning Breaking Change from 1.x → 2.x
+tiptap 1 tried to hide that node from you, but it has always been there. You have to explicitly import it from now on (or use `defaultExtensions()`).
+:::
+
+## Installation
+```bash
+# with npm
+npm install @tiptap/extension-text
+
+# with Yarn
+yarn add @tiptap/extension-text
+```
+
+## Source code
+[packages/extension-text/](https://github.com/ueberdosis/tiptap-next/blob/main/packages/extension-text/)
+
+## Usage
+<demo name="Extensions/Text" highlight="12,30" />