Add config custom color in notification-message

Ex.: &4Need to wait 2 seconds to use ItemFrame!

Colors:

• 0 - black
• 1 - dark.blue
• 2 - green
• 3 - dark.aqua
• 4 - red
• 5 - purple
• 6 - gold
• 7 - grey
• 8 - dark.grey
• 9 - blue
• a - light.green
• b - aqua
• c - light.red
• d - magenta
• e - yellow
• f - white

Modifiers:

• k - obfuscated
• l - bold
• m - strikethrough
• n - underlined
• o - italic