chore: use @npmcli/template-oss (#433)

This adds `@npmcli/template-oss` to manage GitHub Actions, linting, and
other chores.

This surfaced a few bugs which I opted to fix in separate issues:

- #432
- #434

Author: lukekarrys

.commitlintrc.js

@@ -0,0 +1,10 @@
+/* This file is automatically added by @npmcli/template-oss. Do not edit. */
+
+module.exports = {
+  extends: ['@commitlint/config-conventional'],
+  rules: {
+    'type-enum': [2, 'always', ['feat', 'fix', 'docs', 'deps', 'chore']],
+    'header-max-length': [2, 'always', 80],
+    'subject-case': [0, 'always', ['lower-case', 'sentence-case', 'start-case']],
+  },
+}

.eslintrc.js

@@ -0,0 +1,14 @@
+/* This file is automatically added by @npmcli/template-oss. Do not edit. */
+
+const { readdirSync: readdir } = require('fs')
+
+const localConfigs = readdir(__dirname)
+  .filter((file) => file.startsWith('.eslintrc.local.'))
+  .map((file) => `./${file}`)
+
+module.exports = {
+  extends: [
+    '@npmcli',
+    ...localConfigs,
+  ],
+}