Better renovate filter for Dockerfiles

Signed-off-by: Mario Loriedo <mario.loriedo@gmail.com>

Author: l0rd

renovate.json

@@ -3,7 +3,10 @@
   "extends": ["config:base"],
   "regexManagers": [
     {
-      "fileMatch": ["^Dockerfile$"],
+      "fileMatch": [
+        "(^|/|\\.)([Dd]ocker|[Cc]ontainer)file$",
+        "(^|/)([Dd]ocker|[Cc]ontainer)file[^/]*$"
+      ],
       "matchStrings": [
         "#\\s*renovate:\\s*datasource=(?<datasource>.*?) depName=(?<depName>.*?)( versioning=(?<versioning>.*?))?\\sENV .*?_VERSION=\"(?<currentValue>.*)\"\\s"
       ],