docs: add README

[mickamy]

No description provided.

[Copilot]

Pull request overview

Adds initial project documentation and release metadata so slog-pretty can be installed/consumed more easily (CLI, library, and packaging).

Changes:

• Add a comprehensive README.md with install/usage examples and option/flag documentation.
• Add an MIT LICENSE.
• Add a .goreleaser.yaml configuration for building archives and publishing a Homebrew formula.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
README.md	Introduces installation/usage docs and lists CLI flags + handler/options.
LICENSE	Adds MIT license text for project distribution.
.goreleaser.yaml	Defines GoReleaser build, archive, and Homebrew tap publishing configuration.

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[Copilot]

The Dockerfile snippet uses ${TARGETARCH} but doesn’t declare it as a build arg. For copy/paste users this typically expands to an empty string and breaks the download URL; declare ARG TARGETARCH (and optionally ARG TARGETOS) before using it, or hardcode the arch in the example.

Suggested change

	```dockerfile
	```dockerfile
	ARG TARGETARCH=amd64

[Copilot]

This example references go run ./cmd/server, but this repository doesn’t have a cmd/server package. Consider changing it to a generic placeholder (e.g., go run ./path/to/your/app | spretty) to avoid users hitting a "directory not found" error.

Suggested change

	go run ./cmd/server | spretty
	go run ./path/to/your/app | spretty