docs: add troubleshooting section for installation

[koko-dodo]

Description

This PR adds a Troubleshooting section to the README.md to help users resolve the zsh: command not found: tvbextxircuits error.

References

None. This PR is based on personal dev-environment setup experience where uv managers are used.

Pull Request Type

• Xircuits Core (Jupyterlab Related changes)
• Xircuits Canvas (Custom RD Related changes)
• Xircuits Component Library
• Xircuits Project Template
• Testing Automation
• Documentation
• Others (Please Specify)

Type of Change

• New feature (non-breaking change which adds functionality)
• Bug fix (non-breaking change which fixes an issue)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Tests

Verification of Troubleshooting Commands

1. Installed the extension in a fresh virtual environment using uv.

2. Verified that tvbextxircuits returned command not found before activation.

3. Executed Option A (manual activation) and confirmed the command worked.

4. Executed Option B (direct path) and confirmed the binary launched correctly.

Tested on? Specify Version.

• Windows
• Linux
• Mac
• Others (State here -> xxx )

Notes

While the main README focuses on conda, many contributors using uv encounter this path issue. I'll be happy if this addition helps contributors using different environment managers.