add more configuration

Author: isabelatkinson

.github/dependabot.yml

@@ -4,5 +4,16 @@ updates:
     directory: /
     schedule:
       interval: weekly
-      reviewers:
-        - "mongodb/dbx-rust"
+    reviewers:
+      - "mongodb/dbx-rust"
+    # Only bump to the latest version compatible with the dependency's version
+    # in Cargo.toml. This is the equivalent of running `cargo update`.
+    versioning-strategy: lockfile-only
+    # Update all dependencies in a single PR.
+    groups:
+      rust-dependencies:
+        patterns:
+          - "*"
+    # Include transitive dependencies.
+    allow:
+      - dependency-type: all