fix: Allow soft breaks in paragraphs with Shift-Enter

closes #3276

shared/editor/nodes/Paragraph.ts

@@ -1,6 +1,9 @@
 import { setBlockType } from "prosemirror-commands";
 import { NodeSpec, NodeType, Node as ProsemirrorNode } from "prosemirror-model";
+import { EditorState } from "prosemirror-state";
 import { MarkdownSerializerState } from "../lib/markdown/serializer";
+import isNodeActive from "../queries/isNodeActive";
+import { Dispatch } from "../types";
 import Node from "./Node";
 
 export default class Paragraph extends Node {
@@ -20,6 +23,14 @@ export default class Paragraph extends Node {
   keys({ type }: { type: NodeType }) {
     return {
       "Shift-Ctrl-0": setBlockType(type),
+      "Shift-Enter": (state: EditorState, dispatch: Dispatch) => {
+        if (!isNodeActive(type)(state)) {
+          return false;
+        }
+
+        dispatch(state.tr.insertText("\n"));
+        return true;
+      },
     };
   }