Add presets

[Maingron]

Add presets.
IP so far:

snowChars: ["*"], // [array] Characters to use for snowflakes (default:["*"]) (e.g. ["*", "❅", "❆"] or for halloween: ["🎃", "👻", "🦇"] or for christmas: ["🎄", "🎅", "🎁"] or for valentine's day: ["❤", "💋", "💝"] or for easter: ["🐰", "🐣", "🐥"] or for 4th of july: ["🇺🇸", "🎆", "🎇"] or for new year: ["🎉", "🎊", "🎈"] or for chinese new year: ["🐷", "🐔", "🐶"] or for hanukkah: ["🕎", "🕍", "🔯"] or for kwanzaa: ["🎋", "🎍", "🎎"] or for st. patrick's day: ["🍀", "🍺", "🍻"] or for thanksgiving: ["🦃", "🍁", "🍂"] or for winter: ["❄", "☃", "⛄"] or for spring: ["🌷", "🌸", "🌹"] or for summer: ["☀", "🌞", "🌻"] or for fall: ["🍂", "🍁", "🍃"]);

// Presets //
    // PRESETS //
    let presets = {
        "default": {
            snowChars: ["*"],
            snowOpacity: 0.75,
        },
        
    };