docs(docs): moved documentation to root docs directory and updated all references

- Moved documentation files from packages/coding-agent/docs/ to root docs/ directory to flatten the documentation structure.
- Updated all internal documentation links to account for the new file locations, adjusting relative paths to maintain correct references across the monorepo.
- Updated README.md and issue template configuration to reference documentation at the new root docs/ location instead of packages/coding-agent/docs/.

.github/ISSUE_TEMPLATE/config.yml

@@ -1,11 +1,11 @@
 blank_issues_enabled: true
 contact_links:
   - name: Model Configuration
-    url: https://github.com/can1357/oh-my-pi/blob/main/packages/coding-agent/docs/models.md
+    url: https://github.com/can1357/oh-my-pi/blob/main/docs/models.md
     about: How to add custom providers and models via models.yml
   - name: Extensions Guide
-    url: https://github.com/can1357/oh-my-pi/blob/main/packages/coding-agent/docs/extensions.md
+    url: https://github.com/can1357/oh-my-pi/blob/main/docs/extensions.md
     about: Build custom tools, commands, and integrations
   - name: Skills Documentation
-    url: https://github.com/can1357/oh-my-pi/blob/main/packages/coding-agent/docs/skills.md
+    url: https://github.com/can1357/oh-my-pi/blob/main/docs/skills.md
     about: How to create and use skills