[Planned Feature] Reduce the size of terrain heightmaps

[Kluskey]

Description
Right now the terrains are massive, which can be difficult for low-end machines and can affect Space start time. Additionally, it can take a long time to fully fill out a terrain to make a game feel "complete", so it's better to start small.

In the future, we'll also allow for multiple terrains

Acceptance Criteria

• Reduce map size by about 85-90%
• The start position should still be at the center of the terrain