Multi-document management (create new document; tab switching) (#210)

* Multi-docs WIP

* Change to number

* Add new document and switch documents

* Remove keybind for previous document. Change keybind for next document.

* Switch documents by clicking tabs

* Remove keybind for previous document. Change keybind for next document.

* multi-docs

* Update package-lock.json

* Hook up File>New to add new document

* Remove console logs and empty lines. Start new documents from 2 instead of 1.

* Fix formatting

client/web/wasm/src/document.rs

@@ -21,6 +21,16 @@ pub fn select_tool(tool: String) -> Result<(), JsValue> {
 	})
 }
 
+#[wasm_bindgen]
+pub fn select_document(document: usize) -> Result<(), JsValue> {
+	EDITOR_STATE.with(|editor| editor.borrow_mut().handle_message(DocumentMessage::SelectDocument(document)).map_err(convert_error))
+}
+
+#[wasm_bindgen]
+pub fn new_document() -> Result<(), JsValue> {
+	EDITOR_STATE.with(|editor| editor.borrow_mut().handle_message(DocumentMessage::NewDocument).map_err(convert_error))
+}
+
 // TODO: When a mouse button is down that started in the viewport, this should trigger even when the mouse is outside the viewport (or even the browser window if the browser supports it)
 /// Mouse movement within the screenspace bounds of the viewport
 #[wasm_bindgen]