Add renovate.json5

Author: fisker

.github/renovate.json5

@@ -0,0 +1,6 @@
+{
+  $schema: "https://docs.renovatebot.com/renovate-schema.json",
+  dependencyDashboardApproval: true,
+  baseBranchPatterns: ["main"],
+  postUpdateOptions: ["yarnDedupeHighest"],
+}