Add AGENTS.md file

[subtleGradient]

This commit adds the AGENTS.md file, which contains guidelines for contributing to the project. This includes information on project structure, build and test commands, coding style, testing guidelines, and commit/pull request guidelines.

[Copilot]

Pull Request Overview

This PR adds comprehensive contribution guidelines to the project by introducing an AGENTS.md file that documents project structure, build commands, coding style, testing procedures, and commit conventions for the libansilove C library.

Key changes:

• Added AGENTS.md with detailed contributor guidelines covering project structure, build/test commands, coding standards, and PR requirements
• Added a CLAUDE.md file that appears to reference AGENTS.md

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
AGENTS.md	Comprehensive contribution guidelines covering project structure, build commands, coding style, testing, and commit conventions
CLAUDE.md	Single line file containing "AGENTS.md" reference

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_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}

[Copilot]

This file contains only a filename reference without any context or explanation. Consider adding documentation explaining the purpose of this file or removing it if it's not needed.

[Copilot]

[nitpick] This paragraph is extremely long and dense, making it difficult to read and understand. Consider breaking it into multiple sentences or using bullet points to improve readability.

Suggested change

	libansilove is a C library that converts ANSI and related art files to PNG. Core headers live in `include/`, while the implementation sits in `src/` with `loaders/` containing format-specific decoders and `fonts/` bundling built-in typefaces. Cross-platform fallbacks are under `compat/`. The `example/` directory shows how to invoke the API end-to-end, and `man/` provides installed manual pages. Dedicated fuzzing harnesses reside in `fuzz/`; build them only when running sanitizer-heavy tests.
	libansilove is a C library that converts ANSI and related art files to PNG. The project is organized as follows:
	- Core headers live in `include/`.
	- The main implementation is in `src/`.
	- `loaders/` contains format-specific decoders.
	- `fonts/` bundles built-in typefaces.
	- Cross-platform fallbacks are under `compat/`.
	- The `example/` directory shows how to invoke the API end-to-end.
	- `man/` provides installed manual pages.
	- Dedicated fuzzing harnesses reside in `fuzz/` (build them only when running sanitizer-heavy tests).