Initial docs on README

Closes #100

Author: jeromekelleher

README.md

@@ -1,5 +1,44 @@
+[![CI](https://github.com/sgkit-dev/vcztools/actions/workflows/ci.yml/badge.svg?branch=main)](https://github.com/sgkit-dev/vcztools/actions/workflows/ci.yml)
+
 # vcztools
-Partial reimplementation of bcftools for VCF Zarr
+Partial reimplementation of bcftools for [VCF Zarr](https://github.com/sgkit-dev/vcf-zarr-spec/)
+
+Please see the [preprint](https://www.biorxiv.org/content/10.1101/2024.06.11.598241) for more information.
+
+
+## Installation
+
+```
+python3 -m pip install vcztools
+```
+
+## Usage
+
+```
+vcztools view <path.vcz>
+```
+or 
+```
+python -m vcztools view <path.vcz>
+```
+should be equivalent to running 
+```
+bcftools view <path.vcf.gz>
+```
+
+See the [bio2zarr](https://sgkit-dev.github.io/bio2zarr/) project for help in 
+converting VCF files to Zarr.
+
+## Goals
+
+Vcztools aims to be a drop-in replacement for a subset of bcftools functionality.
+Currently supported are the ``view``, ``query`` and ``index -s/-n`` commands.
+
+We aim for 100% compatibility so if you notice a difference between the output of 
+vcztools and bcftools please do open an issue.
+
+## Development
 
+Vcztools is under active development and contributions are warmly welcomed. Please 
+see the project on [GitHub](https://github.com/sgkit-dev/vcztools).
 
-**This is an early prototype: DO NOT USE!**