Use dependabot, but only for major versions

Author: jonhoo

.github/dependabot.yml

@@ -0,0 +1,13 @@
+version: 2
+updates:
+  - package-ecosystem: cargo
+    directory: /
+    schedule:
+      interval: daily
+    ignore:
+      dependency-name: "*"
+      # patch and minor updates don't matter for libraries
+      # remove this ignore rule if your package has binaries
+      update-types:
+        - "version-update:semver-patch"
+        - "version-update:semver-minor"