Add eslint and prettier

.github/workflows/check.yml

@@ -0,0 +1,24 @@
+---
+name: Check
+on:
+  - pull_request
+  - push
+
+permissions:
+  contents: read
+  pull-requests: write
+
+jobs:
+  checks:
+    name: Check code quality
+    runs-on: ubuntu-22.04
+    steps:
+      - name: npm install
+        run: |
+          npm ci
+      - name: eslint
+        run: |
+          npm run lint
+      - name: prettier
+        run: |
+          npm run format:check

.gitignore

@@ -0,0 +1 @@
+/node_modules

.yamllint

@@ -2,6 +2,9 @@
 
 extends: default
 
+ignore-from-file:
+  - .gitignore
+
 rules:
   indentation:
     spaces: 2

eslint.config.mjs

@@ -0,0 +1,7 @@
+import globals from "globals";
+import pluginJs from "@eslint/js";
+
+export default [
+  { languageOptions: { globals: globals.node } },
+  pluginJs.configs.recommended,
+];