Add chat format for in-game messages sent via `/me`, `/say`, `/tellraw`, etc. commands

[axieum]

Is your feature request related to a problem?

To be able to configure a chat format for in-game messages triggered by players using the /me <action>, /say <message> and /tellraw commands.

Describe the solution you'd like.

e.g.

{
  "entries": [
    {
      "discord": {
        /*
         * A player sent an in-game chat message via the '/me' command
         * Usages: ${username}, ${player}, ${action} and ${world}
         */
        "emote": "`${world}` **${player}** _${action}_",
        /*
         * An admin broadcast an in-game chat message via the '/say' command
         * Usages: ${username}, ${player} and ${message}
         */
        "say": "[**${player:-Server}**] ${message}",
        /*
         * An admin broadcast an in-game message to all players via the '/tellraw' command
         * Usages: ${message}
         */
        "tellraw": "${message}"
      }
    }
  ]
}

Describe alternatives you've considered.

n/a

Agreements

• [X] I have searched for and ensured there isn't already an open issue regarding this.
• [X] I have ensured the feature I'm requesting isn't already in the latest supported mod version.

Other

No response