[Feature Request] Global Spawn Rate Percent

[BenMac31]

Description: Add a global spawn rate percent to multiply all of the stage specific spawn rates by.

Reason: It is useful for players to be able to quickly determine how much they want to play with procedural stages globally. The current implementation requires the player to manually change 15 different values if they want to change how often they see procedural stages globally.

[Lawlzee]

Hi, I like this idea. It is indeed annoying to have to change 5 * terrain type count config every time. I'll probably do something similar that you suggested