Adds use_terrain_origins option to TerrainImporterCfg

[georgwi]

Description

Support distributing environments in a grid when using a generated terrain.

Fixes #3536

Type of change

• New feature (non-breaking change which adds functionality)

Screenshots

Checklist

• I have read and understood the contribution guidelines
• I have run the pre-commit checks with ./isaaclab.sh --format
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• I have updated the changelog and the corresponding version in the extension's config/extension.toml file
• I have added my name to the CONTRIBUTORS.md or my name already exists there

[Mayankm96]

Could you please update the changelog and extension.toml file? :)

[ooctipus]

Support distributing environments in a grid when using a generated terrain.

Thank you for new feature!!

I am curious in what use cases do you want a generated sub terrain but with grid origin :)

[georgwi]

Appreciate the reviews! I have incremented the version and updated the changelog.

@ooctipus some of the policies I train on the generated terrain stay in one place (jump in place, kneel down). This setting allows me to get a good spread of the robots across the "slopes" terrain, for example. Also I think exported videos look much nicer if the robots are not clumped together.