Document common Ibex development commands

[shrutikbalwan]

Summary

Add a task-oriented command guide to the Getting Started documentation for
common Ibex build, simulation, lint, and compliance workflows.

The guide documents the existing top-level Make targets for:

• Simple System build and simulation
• CSR testbench build and simulation
• RTL and Python lint
• RISC-V compliance target build
• Selecting and inspecting an IBEX_CONFIG

Advanced UVM usage remains in the existing verification guide so setup details
continue to have a single authoritative location.

Testing

• Strict Sphinx HTML build with warnings treated as errors: PASS
• Cross-reference validation for all 36 documentation pages: PASS
• Dry-run/target resolution for every documented Make target: PASS
• git diff --check: PASS

The Sphinx test overrides html_logo with the location of the tracked logo to
work around the existing doc/images/logo.svg configuration mismatch.

Fixes #741

[github-actions]

Thank you for your submission, we really appreciate it.

Like many open-source projects, we ask that you sign the Contributor License Agreement before we can accept your contribution.

The CLA ensures that all users of the project are granted rights to use the submission.

Before signing the CLA, please ensure that you have the authority from your organisation to grant these rights.

You will be asked to sign the CLA when you first contribute to each lowRISC repository, and will be asked to re-sign if the CLA changes.

Each individual who has committed in this Pull Request should sign the CLA by posting a Pull Request Comment containing the text below.

---

I have read the CLA Document. By submitting this pull request comment, I am hereby confirming my acceptance of the terms of the CLA Document and my agreement to be legally bound by its terms.

---

_{You can retrigger this bot by commenting recheck in this Pull Request. Posted by the CLA Assistant Lite bot.}