fix: hooks file for old plugins (#1867)

Author: alexander-akait

.husky/commit-msg

@@ -0,0 +1,7 @@
+// TODO remove in the next major release
+const plugin = require("../index");
+
+module.exports = {
+  getHtmlWebpackPluginHooks: (compilation) =>
+    plugin.getCompilationHooks(compilation),
+};