[Feature]: Documentation for running OpenHands without Docker

[openhands-agent]

What problem or use case are you trying to solve?
Currently, there is no documentation for running OpenHands without Docker. Providing such documentation would help resolve associated issues.

Describe the UX of the solution the user wants
The documentation should detail steps to run OpenHands in a local environment without using Docker.

User's thoughts on the technical implementation?
N/A

Describe the alternatives considered
N/A

Additional context
Links were referenced in the Slack conversation:

• Implementation: Link
• Documentation: Link
• Issues referenced:
  • Issue #6137
  • Issue #426

Issue Created By: Graham Neubig on Slack

Link to Slack Thread: Link to Thread