Documentation needed: Update custom triggers documentation

[Whipstickgostop]

Describe the missing documentation
Add additional context for registering custom triggers within Init()

Where do you think this documentation should be included? An existing page or new page?
https://docs.streamer.bot/guide/triggers#custom-triggers

Additional context
From @Rhondi Discord Post

When registering custom triggers, it's best practice to register them in the public void Init() method. And also adjust the Execute C# Code sub-action to Precompile on Application Start

public void Init()
{
    CPH.RegisterCustomTrigger("New Twitch Clip Found", "clip_found", new[] {"Twitch"});
}

[rondhi]

You can even nest deeper categories this way

public void Init()
{
    CPH.RegisterCustomTrigger("Poll Ended", "poll_ended", new[] {"Chat Based Poll"});
    CPH.RegisterCustomTrigger("Poll Canceled", "poll_canceled", new[] {"Chat Based Poll"});
    CPH.RegisterCustomTrigger("Poll Status", "poll_status", new[] {"Chat Based Poll"});
    CPH.RegisterCustomTrigger("Poll Message Winner", "poll_winner_one", new[] {"Chat Based Poll", "Winner"});
    CPH.RegisterCustomTrigger("Poll Message Tie 2", "poll_winner_two", new[] {"Chat Based Poll", "Winner"});
    CPH.RegisterCustomTrigger("Poll Message Tie 3", "poll_winner_three", new[] {"Chat Based Poll", "Winner"});
}