added eslint-plugin

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

packages/eslint-plugin/index.js

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+module.exports = {
+  configs: {
+    recommended: {
+      plugins: ['@backstage'],
+      rules: {
+        '@backstage/no-forbidden-package-imports': 'error',
+      },
+    },
+  },
+  rules: {
+    'no-forbidden-package-imports': require('./rules/no-forbidden-package-imports'),
+  },
+};