## Summary
Audits and updates litegraph documentation files that came from the old
litegraph.js repo merged via git subtree (per #8341 discussion).
## Changes
- **Delete** `CONTRIBUTING.md` - completely outdated, referenced
original jagenjo/litegraph.js from 2020
- **Fix** `API.md` - remove Subgraph from "Removed public interfaces"
(actively used in 25+ files)
- **Update** `README.md` - replace standalone releasing instructions
with note about embedded subtree workflow
- **Fix** `AGENTS.md` and `__fixtures__/README.md` - correct import path
typos (`./fixtures/` → `./__fixtures__/`)
Fixes#8347
cc @DrJKL
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
## Documentation
* Updated release information to clarify that the library is embedded
via git subtree and managed through the parent repository's release
process
* Removed contribution guidelines documentation file
* Updated API documentation by removing Subgraph from the list of
removed public interfaces
* Updated documentation examples to align with current project structure
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-8588-docs-audit-and-update-litegraph-documentation-2fc6d73d365081fca335c78ce8493d3e)
by [Unito](https://www.unito.io)
