Add skill-image-gen plugin: AI image generation with OpenAI and Gemini (#1696)

Adds a skill that lets users generate images (icons, sprites, textures,
mockups) directly from their coding workflow using OpenAI gpt-image-2 or
Google Gemini. BYO API key — the skill guides users through setup on
first use.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

docs/README.plugins.md

@@ -83,6 +83,7 @@ See [CONTRIBUTING.md](../CONTRIBUTING.md#adding-plugins) for guidelines on how t
 | [rust-mcp-development](../plugins/rust-mcp-development/README.md) | Build high-performance Model Context Protocol servers in Rust using the official rmcp SDK with async/await, procedural macros, and type-safe implementations. | 2 items | rust, mcp, model-context-protocol, server-development, sdk, tokio, async, macros, rmcp |
 | [salesforce-development](../plugins/salesforce-development/README.md) | Complete Salesforce agentic development environment covering Apex & Triggers, Flow automation, Lightning Web Components, Aura components, and Visualforce pages. | 7 items | salesforce, apex, triggers, lwc, aura, flow, visualforce, crm, salesforce-dx |
 | [security-best-practices](../plugins/security-best-practices/README.md) | Security frameworks, accessibility guidelines, performance optimization, and code quality best practices for building secure, maintainable, and high-performance applications. | 1 items | security, accessibility, performance, code-quality, owasp, a11y, optimization, best-practices |
+| [skill-image-gen](../plugins/skill-image-gen/README.md) | Generate images using AI directly from your coding workflow. Supports OpenAI (gpt-image-2) and Google Gemini. BYO API key — the skill guides you through setup on first use. | 1 items | image-generation, openai, gemini, ai, art, sprites, textures, icons |
 | [software-engineering-team](../plugins/software-engineering-team/README.md) | 7 specialized agents covering the full software development lifecycle from UX design and architecture to security and DevOps. | 7 items | team, enterprise, security, devops, ux, architecture, product, ai-ethics |
 | [structured-autonomy](../plugins/structured-autonomy/README.md) | Premium planning, thrifty implementation | 3 items |  |
 | [swift-mcp-development](../plugins/swift-mcp-development/README.md) | Comprehensive collection for building Model Context Protocol servers in Swift using the official MCP Swift SDK with modern concurrency features. | 2 items | swift, mcp, model-context-protocol, server-development, sdk, ios, macos, concurrency, actor, async-await |

docs/README.skills.md

@@ -173,6 +173,7 @@ See [CONTRIBUTING.md](../CONTRIBUTING.md#adding-skills) for guidelines on how to
 | [gdpr-compliant](../skills/gdpr-compliant/SKILL.md)<br />`gh skills install github/awesome-copilot gdpr-compliant` | Apply GDPR-compliant engineering practices across your codebase. Use this skill whenever you are designing APIs, writing data models, building authentication flows, implementing logging, handling user data, writing retention/deletion jobs, designing cloud infrastructure, or reviewing pull requests for privacy compliance. Trigger this skill for any task involving personal data, user accounts, cookies, analytics, emails, audit logs, encryption, pseudonymization, anonymization, data exports, breach response, CI/CD pipelines that process real data, or any question framed as "is this GDPR-compliant?". Inspired by CNIL developer guidance and GDPR Articles 5, 25, 32, 33, 35. | `references/Security.md`<br />`references/data-rights.md` |
 | [gen-specs-as-issues](../skills/gen-specs-as-issues/SKILL.md)<br />`gh skills install github/awesome-copilot gen-specs-as-issues` | This workflow guides you through a systematic approach to identify missing features, prioritize them, and create detailed specifications for implementation. | None |
 | [generate-custom-instructions-from-codebase](../skills/generate-custom-instructions-from-codebase/SKILL.md)<br />`gh skills install github/awesome-copilot generate-custom-instructions-from-codebase` | Migration and code evolution instructions generator for GitHub Copilot. Analyzes differences between two project versions (branches, commits, or releases) to create precise instructions allowing Copilot to maintain consistency during technology migrations, major refactoring, or framework version upgrades. | None |
+| [generate-image](../skills/generate-image/SKILL.md)<br />`gh skills install github/awesome-copilot generate-image` | Generate images using AI. Use when asked to generate, create, or make images, textures, icons, sprites, artwork, visual assets, or mockups. Supports OpenAI (gpt-image-2) and Google Gemini (Nano Banana). Requires an API key for the chosen provider. | None |
 | [geofeed-tuner](../skills/geofeed-tuner/SKILL.md)<br />`gh skills install github/awesome-copilot geofeed-tuner` | Use this skill whenever the user mentions IP geolocation feeds, RFC 8805, geofeeds, or wants help creating, tuning, validating, or publishing a self-published IP geolocation feed in CSV format. Intended user audience is a network operator, ISP, mobile carrier, cloud provider, hosting company, IXP, or satellite provider asking about IP geolocation accuracy, or geofeed authoring best practices. Helps create, refine, and improve CSV-format IP geolocation feeds with opinionated recommendations beyond RFC 8805 compliance. Do NOT use for private or internal IP address management — applies only to publicly routable IP addresses. | `assets/example`<br />`assets/iso3166-1.json`<br />`assets/iso3166-2.json`<br />`assets/small-territories.json`<br />`references/rfc8805.txt`<br />`references/snippets-python3.md`<br />`scripts/templates` |
 | [git-commit](../skills/git-commit/SKILL.md)<br />`gh skills install github/awesome-copilot git-commit` | Execute git commit with conventional commit message analysis, intelligent staging, and message generation. Use when user asks to commit changes, create a git commit, or mentions "/commit". Supports: (1) Auto-detecting type and scope from changes, (2) Generating conventional commit messages from diff, (3) Interactive commit with optional type/scope/description overrides, (4) Intelligent file staging for logical grouping | None |
 | [git-flow-branch-creator](../skills/git-flow-branch-creator/SKILL.md)<br />`gh skills install github/awesome-copilot git-flow-branch-creator` | Intelligent Git Flow branch creator that analyzes git status/diff and creates appropriate branches following the nvie Git Flow branching model. | None |