[documentation] Note that games need to be downloaded before running in the offline OperationMode

[suryabdev]

If you try to use offline mode with a game not available locally, You get the following Game ls20 not found in scanned environments error. This is expected behavior

2026-03-10 13:02:06 | INFO | Created new scorecard: 2ad6657a-b9a4-4d69-9966-024fed86a6bb
INFO:arc_agi.base:Created new scorecard: 2ad6657a-b9a4-4d69-9966-024fed86a6bb
2026-03-10 13:02:06 | ERROR | Game ls20 not found in scanned environments. Available games: []
ERROR:arc_agi.base:Game ls20 not found in scanned environments. Available games: [] 

Adding a note to the Local Vs Online doc stating that games need to be downloaded before OFFLINE mode can be used would make it clearer

Based on my understanding of the code,
OperationMode.NORMAL (default) - Downloads the game and runs in locally
OperationMode.OFFLINE - Searches the local environments directory to load games
OperationMode.ONLINE - User the arg-agi-3 remote environment/rest api
https://github.com/arcprize/ARC-AGI/blob/c80caea7aee6078a0d34ea55c6f93da58c22bc68/arc_agi/base.py#L639

Perhaps, add a note here
https://github.com/arcprize/docs/blob/9dc7724e7356c2055f5c9f5f1f470f706a071a93/local-vs-online.mdx#local

That says,
Note: Local mode scans for downloaded games. To download the game use the normal OperationMode (default value) once

arc = Arcade(operation_mode=OperationMode.OFFLINE)
env = arc.make("ls20", render_mode="terminal")```