Documentation changes

1. Removing the yarn and pnpm installation instructions: these make it way harder to debug. Even with just npm there are complications from different node versions, nvm, etc. Let's keep it simple.
2. Adding more troubleshooting cases: David Aviles and an Anaconda guy ran into needing to use sudo this week, having both packages confuses our customers and makes it harder to debug for them, and we never mention what to do when CLI doesn't match web (probably a top CLI bug report)

For Reviewers

When reviewing documentation PRs, please consider:

✅ Technical accuracy

• Code examples work as written
• Commands and configurations are correct
• Links resolve to the right destinations
• Prerequisites and requirements are accurate

✅ Clarity and completeness

• Instructions are clear and easy to follow
• Steps are in logical order
• Nothing important is missing
• Examples help illustrate the concepts

✅ User experience

• A new user could follow these docs successfully
• Common gotchas or edge cases are addressed
• Error messages or troubleshooting guidance is helpful