Add Dependabot support

Author: artembilan

.github/dependabot.yml

@@ -0,0 +1,23 @@
+version: 2
+updates:
+  - package-ecosystem: "gradle"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+      day: "saturday"
+    ignore:
+      - dependency-name: "*"
+        update-types: ["version-update:semver-major", "version-update:semver-minor"]
+    open-pull-requests-limit: 10
+    groups:
+       development-dependencies:
+         update-types: ["patch"]
+         patterns: 
+         - "com.gradle.enterprise"
+         - "io.spring.*"
+         - "org.ajoberstar.grgit"
+         - "org.antora"
+         - "io.micrometer:micrometer-docs-generator"
+         - "org.hibernate.validator:hibernate-validator"
+         - "org.awaitility:awaitility"
+         - "com.google.code.findbugs:jsr305"