Replace Collections with Plugins as first-class citizens in the repo.
With the Copilot CLI v0.409 release making plugins an on-by-default
marketplace, collections are redundant overhead.
## What changed
### Plugin Infrastructure
- Created eng/validate-plugins.mjs (replaces validate-collections.mjs)
- Created eng/create-plugin.mjs (replaces create-collection.mjs)
- Enhanced all 42 plugin.json files with tags, featured, display, and
items metadata from their corresponding collection.yml files
### Build & Website
- Updated eng/update-readme.mjs to generate plugin docs
- Updated eng/generate-website-data.mjs to emit plugins.json with full
items array for modal rendering
- Renamed website collections page to plugins (/plugins/)
- Fixed plugin modal to use <div> instead of <pre> for proper styling
- Updated README.md featured section from Collections to Plugins
### Documentation & CI
- Updated CONTRIBUTING.md, AGENTS.md, copilot-instructions.md, PR template
- Updated CI workflows to validate plugins instead of collections
- Replaced docs/README.collections.md with docs/README.plugins.md
### Cleanup
- Removed eng/validate-collections.mjs, eng/create-collection.mjs,
eng/collection-to-plugin.mjs
- Removed entire collections/ directory (41 .collection.yml + .md files)
- Removed parseCollectionYaml from yaml-parser.mjs
- Removed COLLECTIONS_DIR from constants.mjs
Closes#711
* initial prototype of partners collection with featured collection support
* Starting to add the partners
* Preparing the repo for how the custom agents will work
* moving some files around
* Moving a bunch of stuff around to make the file easier to read
* improving the front matter parsing by using a real library
* Some verbage updates
* some more verbage
* Fixing spelling mistake
* tweaking badges
* Updating contributing guide to be correct
* updating casing to match product
* More agents
* Better handling link to mcp registry
* links to install mcp servers fixed up
* Updating collection tags
* writing the mcp registry url out properly
* Adding custom agents for C# and WinForms
Expert custom agents to improve your experience when working with C# and WinForms in Copilot
* Adding to agents readme
* Adding PagerDuty agent
* Fixing description for terraform agent
* Adding custom agents to the README usage
* Removing the button to make the links more obvious
* docs: relocate category READMEs to /docs and update generation + internal links
* Updating prompts for new path
* formatting
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Co-authored-by: Chris Patterson <chrispat@github.com>
