fix(renovate): automerge minor and patch versions of used container images in docker files

Dockerfile

@@ -1,4 +1,4 @@
-FROM docker.io/library/rust:slim-buster AS build
+FROM docker.io/library/rust:1.70.0-slim-buster AS build
 
 ARG RPMBUILDER_VERSION=master
 

renovate.json

@@ -11,6 +11,14 @@
       "matchManagers": "droneci",
       "matchUpdateTypes": [ "minor", "patch"]
     },
+    {
+      "description": "Automatically update minor and patch versions of used container images in docker files",
+      "addLabels": [ "renovate/container-image", "renovate/automerge" ],
+      "automerge": true,
+      "matchBaseBranches": [ "master" ],
+      "matchManagers": [ "dockerfile" ],
+      "matchUpdateTypes": [ "minor", "patch" ]
+    },
     {
       "addLabels": [ "renovate/rpm-builder", "renovate/automerge" ],
       "automerge": false,