hlint-matcher.json

{
    "problemMatcher": [
        {
            "owner": "hlint",
            "severity": "warning",
            "pattern": [
                {
                    "regexp": "^([^:]*\\/)([^:/]*):(\\d+)(-\\d+)?:(\\d+)(-\\d+)?: (Warning|Error): (.*)$",
                    "fromPath": 1,
                    "file": 2,
                    "line": 3,
                    "column": 5,
                    "message": 8
                }
            ]
        },
        {
            "owner": "hlint-multiline",
            "severity": "warning",
            "pattern": [
                {
                    "regexp": "^([^:]*\\/)([^:/]*):\\((\\d+),(\\d+)\\)-\\(\\d+,\\d+\\): (Warning|Error): (.*)$",
                    "fromPath": 1,
                    "file": 2,
                    "line": 3,
                    "column": 4,
                    "message": 6
                }
            ]
        }
    ]
}

GitHub Actions Problem Matcher for HLint (creates PR annotations based on log output).

You can register this (before running hlint), by running

echo "::add-matcher::hlint-matcher.json"  

Matches the first line of each warning.

As written, this only matches the more severe "Warning" level suggestions, and not "Suggestions".
You can change this by replacing (Warning|Error) with (Suggestion|Warning|Error) in the two regular expressions.