feature request: associate srs to geoparquet

[Andrea Borruso]

Hi,
I have converted to geoparquet a parquet file, using gpq convert.
And in the metadata I do not have the coordinate reference system info:

"metadata": {
    "version": "",
    "primary_column": "geometry",
    "columns": {
      "geometry": {
        "encoding": "WKB",
        "geometry_types": [
          "Polygon",
          "MultiPolygon"
        ],
        "bbox": [
          313279.2514000004,
          3933846.2156000007,
          1312016.1506000003,
          5220292.292199999
        ]
      }
    }
  }

It would be useful to have a cli option in convert command, something like ogr2ogr: gpq convert -a_srs EPSG:32633.

Thank you for this useful tool