Karabiner-Elementsで option + a で 未読チャネルにジャンプする

slack.json

{
  "title": "For Slack option + a move unread channel",
  "rules": [
    {
      "description": "Remap left_option + left_shift + down_arrow to left_option + a",
      "manipulators": [
        {
          "from": {
            "key_code": "a",
            "modifiers": {
              "mandatory": [
                "left_option"
              ],
              "optional": [
                "any"
              ]
            }
          },
          "to": [
            {
              "key_code": "down_arrow",
              "modifiers": [
                "left_option",
                "left_shift"
              ]
            }
          ],
         "conditions": [
           {
             "type": "frontmost_application_if",
             "bundle_identifiers": [
               "com.tinyspeck.slackmacgap"
             ]
           }
         ],
         "type": "basic"
        }
      ]
    }
  ]
}