chore: add grouping rules to renovate.json (#31)

Author: dsayling

renovate.json

@@ -1,4 +1,31 @@
 {
   "$schema": "https://docs.renovatebot.com/renovate-schema.json",
-  "extends": ["config:recommended"]
+  "extends": ["config:recommended"],
+  "packageRules": [
+    {
+      "description": "Group all non-major npm dependencies",
+      "matchManagers": ["npm"],
+      "matchUpdateTypes": ["minor", "patch"],
+      "groupName": "npm dependencies (non-major)",
+      "groupSlug": "npm-minor-patch"
+    },
+    {
+      "description": "Group Docusaurus packages",
+      "matchPackagePatterns": ["^@docusaurus/"],
+      "groupName": "Docusaurus",
+      "groupSlug": "docusaurus"
+    },
+    {
+      "description": "Group React packages",
+      "matchPackagePatterns": ["^react", "^@mdx-js/react"],
+      "groupName": "React ecosystem",
+      "groupSlug": "react"
+    },
+    {
+      "description": "Group all GitHub Actions updates",
+      "matchManagers": ["github-actions"],
+      "groupName": "GitHub Actions",
+      "groupSlug": "github-actions"
+    }
+  ]
 }