Function setMaterialSpeed

Set Material mining speed

Common values:

• 1.5 => Blue / Green Slime
• 2.0 => Paper
• 3.5 => Wood
• 4.0 => Stone
• 5.0 => Cactus
• 6.0 => Iron
• 7.0 => Obsidian
• 8.0 => Alumite
• 9.0 => Manyullyn
• 14.0 => Cobalt