Group PR's for eslint-related deps (#374)

There are multiple deps that are `eslint`-related, and since they're all related to a linter, it's very safe to merge them as a single group.

So try kicking the tires on the new "grouping" feature that the  team is working on.

Author: jeffwidman

.github/dependabot.yml

@@ -8,3 +8,7 @@ updates:
     directory: "/"
     schedule:
       interval: "monthly"
+    groups:
+      eslint-dependencies:
+        patterns:
+          - "*eslint*"