Add human-readable specification document

README.md

@@ -1,7 +1,15 @@
 # Palette Format Specification
 
 This repository contains the specification for the Palette XML format, a simple
-format for representing colour palettes.
+format for representing colour palettes. The specification consists of a
+human-readable document and an XSD schema.
+
+
+## Contents
+
+- [`spec.md`](spec.md) — The human-readable specification
+- [`palette.xsd`](palette.xsd) — The XSD schema for document validation
+
 
 ## Overview
 
@@ -21,6 +29,7 @@ This namespace identifies version 1 of the format. A new namespace will be
 introduced only if a future version of the format introduces breaking changes.
 Backwards-compatible additions do not result in a new namespace.
 
+
 ## Versioning
 
 This specification follows [Semantic Versioning](https://semver.org/):
@@ -36,6 +45,7 @@ element of [`palette.xsd`](palette.xsd).
 Git tags correspond directly to specification versions and are prefixed with `v`
 (e.g. `v1.0.0`, `v1.1.0`).
 
+
 ## Licence
 
 This specification is copyright Mark Embling and is licensed under
@@ -44,6 +54,7 @@ This specification is copyright Mark Embling and is licensed under
 You are free to share and adapt the specification for any purpose, provided you give
 appropriate attribution and distribute any derivative specifications under the same licence.
 
+
 ### Implementing this Specification
 
 Implementing this specification in software — including commercial software — is