allow disabling indentation for specific nodes via IndentFeature
Usage:
```ts
editor: lexicalEditor({
features: ({ defaultFeatures }) => [
...defaultFeatures,
IndentFeature({
// the array must contain the "type" property of registered indentable nodes
disabledNodes: ['paragraph', 'listitem'],
}),
],
}),
```
The nodes "paragraph", "heading", "listitem", "quote" remain indentable
by default, even without `IndentFeature` registered.
In a future PR we will probably add the option to disable TabNode.
eb09ce9a3e