chore: add renovate config (#53)

Co-authored-by: Jack Wotherspoon <[email protected]>

Author: enocom

.github/renovate.json

@@ -1,17 +1,20 @@
 {
-    "extends": [
-      "config:base",
-      ":semanticCommitTypeAll(chore)",
-      "helpers:pinGitHubActionDigests"
-    ],
-    "commitMessagePrefix": "deps: ",
-    "ignorePresets": [":semanticPrefixFixDepsChoreOthers"],
-    "ignorePaths": [".kokoro/requirements.txt"],
-    "prConcurrentLimit": 0,
-    "rebaseStalePrs": true,
-    "dependencyDashboard": true,
-    "semanticCommits": false,
-    "pip_requirements": {
-      "fileMatch": ["requirements-test.txt"]
-    }
-  }
+  "extends": [
+    "config:base",
+    ":semanticCommitTypeAll(chore)",
+    "helpers:pinGitHubActionDigests"
+  ],
+  "commitMessagePrefix": "deps: ",
+  "ignorePresets": [":semanticPrefixFixDepsChoreOthers"],
+  "ignorePaths": [".kokoro/requirements.txt"],
+  "prConcurrentLimit": 0,
+  "rebaseStalePrs": true,
+  "dependencyDashboard": true,
+  "semanticCommits": false,
+  "pip_requirements": {
+    "fileMatch": ["requirements-test.txt"]
+  },
+  "schedule": [
+    "before 4am on the first day of the month"
+  ]
+}