Other file types support

[kerunaru]

Add support for updating the version of other files (in principle json, such as Chart.yaml)

[sergiotejon]

In the version.json fill we can this version_files list, like this example:

{
    "version": "0.18.1",
    "commit": "72929b90547b8527e22e402b6784e0c7f5812428",
    "version_files": [
        "Chart.yaml:version",
        "other-version.txt:version"
    ],
    "prefix": ""
}