selene Lua linter problem matcher for GitHub Actions.

selene.json

{
  "problemMatcher": [
    {
      "owner": "selene",
      "pattern": [
        {
          "regexp": "^(error|warning|info)\\[(.*)\\]:\\s(.*)$",
          "severity": 1,
          "message": 3,
          "code": 2
        },
        {
          "regexp": "^\\s+\\u250C\\u2500\\s(.*):(\\d+):(\\d+)$",
          "file": 1,
          "line": 2,
          "column": 3
        }
      ]
    }
  ]
}