chore(config): migrate renovate config (#936)

* chore(config): migrate config .github/renovate.json

* Apply suggestions from code review

---------

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: Michael Kriese <[email protected]>

Author: renovate[bot]

.github/renovate.json

@@ -55,7 +55,7 @@
   "customManagers": [
     {
       "customType": "regex",
-      "fileMatch": ["^README\\.md$"],
+      "managerFilePatterns": ["README.md"],
       "matchStrings": [
         "uses: renovatebot/github-action@(?<currentValue>[^\\s]+)"
       ],
@@ -64,23 +64,23 @@
     },
     {
       "customType": "regex",
-      "fileMatch": ["^README\\.md$"],
+      "managerFilePatterns": ["README.md"],
       "matchStrings": ["renovate-version: (?<currentValue>[^\\s]+)"],
       "depNameTemplate": "ghcr.io/renovatebot/renovate",
       "datasourceTemplate": "docker"
     },
     {
       "description": "Update renovate version in action.yml",
       "customType": "regex",
-      "fileMatch": ["^action\\.yml$"],
+      "managerFilePatterns": ["action.yml"],
       "matchStrings": ["default: '(?<currentValue>[^\\s]+)' # renovate"],
       "depNameTemplate": "ghcr.io/renovatebot/renovate",
       "datasourceTemplate": "docker"
     },
     {
       "description": "Update renovate version in src/docker.ts",
       "customType": "regex",
-      "fileMatch": ["^src/docker\\.ts$"],
+      "managerFilePatterns": ["src/docker.ts"],
       "matchStrings": ["version = '(?<currentValue>[^\\s]+)'; // renovate"],
       "depNameTemplate": "ghcr.io/renovatebot/renovate",
       "datasourceTemplate": "docker"