Add plugins for all collections

Generate plugin directories for 36 collections not previously represented:
- awesome-copilot, cast-imaging, clojure-interactive-programming, copilot-sdk
- csharp-dotnet-development, csharp-mcp-development, database-data-management
- dataverse-sdk-for-python, devops-oncall, edge-ai-tasks, frontend-web-dev
- go-mcp-development, java-development, java-mcp-development, kotlin-mcp-development
- mcp-m365-copilot, openapi-to-application-* (5 variants), partners
- pcf-development, php-mcp-development, power-apps-code-apps, power-bi-development
- power-platform-mcp-connector-development, python-mcp-development
- ruby-mcp-development, rust-mcp-development, security-best-practices
- structured-autonomy, swift-mcp-development, technical-spike
- typescript-mcp-development, typespec-m365-copilot

Each plugin includes:
- .github/plugin/plugin.json with metadata
- README.md with installation instructions
- Symlinks to canonical agents, commands, and skills

Updated marketplace.json to include all 40 plugins.

plugins/partners/README.md

@@ -0,0 +1,45 @@
+# Partners Plugin
+
+Custom agents that have been created by GitHub partners
+
+## Installation
+
+```bash
+# Using Copilot CLI
+copilot plugin install github/awesome-copilot/plugins/partners
+```
+
+## What's Included
+
+### Agents
+
+| Agent | Description |
+|-------|-------------|
+| `amplitude-experiment-implementation` | Amplitude Experiment Implementation |
+| `apify-integration-expert` | Apify Integration Expert |
+| `arm-migration` | Arm Migration |
+| `diffblue-cover` | Diffblue Cover |
+| `droid` | Droid |
+| `dynatrace-expert` | Dynatrace Expert |
+| `elasticsearch-observability` | Elasticsearch Observability |
+| `jfrog-sec` | Jfrog Sec |
+| `launchdarkly-flag-cleanup` | Launchdarkly Flag Cleanup |
+| `lingodotdev-i18n` | Lingodotdev I18N |
+| `monday-bug-fixer` | Monday Bug Fixer |
+| `mongodb-performance-advisor` | Mongodb Performance Advisor |
+| `neo4j-docker-client-generator` | Neo4J Docker Client Generator |
+| `neon-migration-specialist` | Neon Migration Specialist |
+| `neon-optimization-analyzer` | Neon Optimization Analyzer |
+| `octopus-deploy-release-notes-mcp` | Octopus Deploy Release Notes Mcp |
+| `stackhawk-security-onboarding` | Stackhawk Security Onboarding |
+| `terraform` | Terraform |
+| `pagerduty-incident-responder` | Pagerduty Incident Responder |
+| `comet-opik` | Comet Opik |
+
+## Source
+
+This plugin is part of [Awesome Copilot](https://github.com/github/awesome-copilot), a community-driven collection of GitHub Copilot extensions.
+
+## License
+
+MIT