feat: color randomization / color resolution

[sudojunior]

A bit of a two in one, color might also be of some use to expand this later on.

TypeScript, in it's standard use, would only allow color to be of type number, but some things can be worked around if it needs to be done.

if (Array.isArray(embed.color)) embed.color = randomItem(embed.color);
else if (embed.color === 'RANDOM') embed.color = Math.ceil(Math.random() * 0xFFFFFF);
else if (embed.color.startsWith('#')) embed.color = parseInt(embed.color.replace(/^#?/, ''), 16);