Add Dependabot grouping for eslint deps (#36)

Add group for eslint deps

Author: danbarr

.github/dependabot.yaml

@@ -8,6 +8,9 @@ updates:
       docusaurus:
         patterns:
           - '*docusaurus*'
+      eslint:
+        patterns:
+          - '*eslint*'
     ignore:
       # Pin key docusaurus dependencies to major versions
       - dependency-name: '@mdx-js/react'