feat: add renovate configs

1. base.json5 is applicable to all projects
2. eslint-base.json5 extends base.json5 and adds ESLint related configurations

Author: aladdin-add

.github/renovate/base.json5

@@ -0,0 +1,27 @@
+{
+  $schema: "https://docs.renovatebot.com/renovate-schema.json",
+  extends: [
+    "config:recommended",
+    ":approveMajorUpdates",
+    ":semanticCommitScopeDisabled",
+  ],
+  ignorePresets: [":semanticPrefixFixDepsChoreOthers"],
+  labels: ["dependencies"],
+
+  // Wait well over npm's three day window for any new package as a precaution against malicious publishes
+  // https://docs.npmjs.com/policies/unpublish/#packages-published-less-than-72-hours-ago
+  minimumReleaseAge: "7 days",
+
+  packageRules: [
+    {
+      description: "Use the deps:actions label for github-action manager updates (this means Renovate's github-action manager).",
+      addLabels: ["deps:actions"],
+      matchManagers: ["github-actions"],
+    },
+    {
+      description: "Use the deps:npm label for npm manager packages (this means Renovate's npm manager).",
+      addLabels: ["deps:npm"],
+      matchManagers: ["npm"],
+    },
+  ],
+}

.github/renovate/eslint-base.json5

@@ -0,0 +1,13 @@
+{
+  $schema: "https://docs.renovatebot.com/renovate-schema.json",
+  extends: ["github>eslint/workflows//.github/renovate/base.json5"],
+  packageRules: [
+    {
+      description: "Update ESLint packages together.",
+      groupName: "eslint",
+      matchPackagePrefixes: ["@eslint/"],
+      matchPackageNames: ["espree", "eslint-scope", "eslint-visitor-keys"],
+      minimumReleaseAge: null, // Don't wait for these packages
+    },
+  ],
+}