add horizontal rule extension

packages/core/src/inputRules/nodeInputRule.ts

@@ -0,0 +1,15 @@
+import { InputRule } from 'prosemirror-inputrules'
+import { NodeType } from 'prosemirror-model'
+
+export default function (regexp: RegExp, type: NodeType, getAttrs?: Function) {
+  return new InputRule(regexp, (state, match, start, end) => {
+    const attrs = getAttrs instanceof Function ? getAttrs(match) : getAttrs
+    const { tr } = state
+
+    if (match[0]) {
+      tr.replaceWith(start - 1, end, type.create(attrs))
+    }
+
+    return tr
+  })
+}