docs: fix broken documentation links in README

[arminazimi]

Summary

• Fixed outdated documentation links in README.md.
• Updated references to their current official destinations.
• Preserved existing documentation structure.

Changes Made

1. Go SDK docs (line 10): →
2. Coroutines - deterministic Workflow (line 68): →
3. Cron Workflow - What is a Temporal Cron Job? (line 78): →
4. Query Example - How to Query a Workflow Execution in Go (line 98): →
5. Selectors - Go SDK Selectors (line 101): →
6. Selectors - deterministic Workflow (line 102): →
7. Sessions - How to use Sessions in Go (line 111): →
8. Signals - eCommerce application tutorial (line 115): →
9. Tracing and Context Propagation - How to use tracing in Go (line 136): →

Validation

• Verified all updated links return HTTP 200.
• Confirmed replacement pages contain the intended information.
• Checked Markdown formatting.
• Reviewed the final diff.

Fixes #488

[CLAassistant]

All committers have signed the CLA.