Document new fields in resolved channel objects

[Sacul0457]

This PR updates what fields a resolved channel object has, or in this case what fields that are always missing.
I added the '(always)' because certain channel types do not have a field that other channel types have, but that doesn't mean it's always missing.

ForumChannel

{
  "type": 15,
  "topic": "..."
  "theme_color": null,
  "template": "",
  "rate_limit_per_user": 10800,
  "position": 18,
  "permissions": "2258386414333638",
  "parent_id": "1141177805753815180",
  "nsfw": false,
  "name": "\u2753\uff5csupport-thread",
  "last_message_id": "1435907872524468255",
  "id": "1141179304269598751",
  "icon_emoji": {
    "name": "\ud83e\uddf5",
    "id": null
  },
  "guild_id": "820745488231301210",
  "flags": 16,
  "default_thread_rate_limit_per_user": 5,
  "default_tag_setting": "match_some",
  "default_sort_order": 0,
  "default_reaction_emoji": null,
  "default_forum_layout": 1,
  "available_tags": [
    {
      "name": "Resolved",
      "moderated": true,
      "id": "1144008960966402149",
      "emoji_name": "\u2705",
      "emoji_id": null,
      "color": null
    },
    {
      "name": "Waiting for Update",
      "moderated": true,
      "id": "1284733312501420145",
      "emoji_name": "\ud83d\udd70\ufe0f",
      "emoji_id": null,
      "color": null
    }
  ]
}

TextChannel

{
  "type": 0,
  "topic": null,
  "theme_color": null,
  "rate_limit_per_user": 0,
  "position": 16,
  "permissions": "9007199254740991",
  "parent_id": null,
  "nsfw": false,
  "name": "idk",
  "last_message_id": null,
  "id": "1435954722136657993",
  "icon_emoji": null,
  "guild_id": "1294290832219963563",
  "flags": 0,
  "default_thread_rate_limit_per_user": 40,
  "default_auto_archive_duration": 60
}

VoiceChannel

{
  "user_limit": 2,
  "type": 2,
  "rtc_region": null,
  "rate_limit_per_user": 0,
  "position": 4,
  "permissions": "9007199254740991",
  "parent_id": "1395762400413745254",
  "nsfw": false,
  "name": "\ud83e\udec2\uff5cDuo",
  "last_message_id": "1401965728390844466",
  "id": "1395772822336573441",
  "guild_id": "1368569405117825095",
  "flags": 0,
  "bitrate": 64000
}

ForumChannel Thread

{
  "type": 11,
  "total_message_sent": 43,
  "thread_metadata": {
    "locked": false,
    "create_timestamp": "2025-11-03T15:17:13.863000+00:00",
    "auto_archive_duration": 4320,
    "archived": false,
    "archive_timestamp": "2025-11-03T15:17:13.863000+00:00"
  },
  "rate_limit_per_user": 5,
  "permissions": "2258386414333638",
  "parent_id": "1141179304269598751",
  "owner_id": "767619541457960980",
  "name": "...",
  "message_count": 41,
  "member_ids_preview": [
    "651551210125524998",
    "802167689011134474",
    "767619541457960980",
    "218427603944472577",
    "1274221442036400137"
  ],
  "member_count": 7,
  "last_pin_timestamp": "2025-11-03T15:17:14.446000+00:00",
  "last_message_id": "1435657005493911692",
  "id": "1434924388662378696",
  "guild_id": "820745488231301210",
  "flags": 0,
  "applied_tags": [
    "1141179662337323008"
  ]
}