update package godocs and root level README for v2

While at it, make v2's license a symlink, so the two stay in sync.
The reason we want the v2 module to have its own license is so that its
module zip includes the file as well.

Besides mentioning v0 and v2, the root README now also links to pkgsite
and lists Masih and myself as default maintainers, given that we're the
ones that did major work on this library last.

Fixes #124.
Fixes #179.

README.md

@@ -4,17 +4,24 @@ go-car (go!)
 [![](https://img.shields.io/badge/made%20by-Protocol%20Labs-blue.svg?style=flat-square)](https://protocol.ai)
 [![](https://img.shields.io/badge/project-ipld-orange.svg?style=flat-square)](https://github.com/ipld/ipld)
 [![](https://img.shields.io/badge/freenode-%23ipld-orange.svg?style=flat-square)](https://webchat.freenode.net/?channels=%23ipld)
+[![Go Reference](https://pkg.go.dev/badge/github.com/ipld/go-car.svg)](https://pkg.go.dev/github.com/ipld/go-car)
 [![Coverage Status](https://codecov.io/gh/ipld/go-car/branch/master/graph/badge.svg)](https://codecov.io/gh/ipld/go-car/branch/master)
 
-> go-car is a simple way of packing a merkledag into a single file
+> A library to interact with merkledags stored as a single file
 
+This is an implementation in Go of the [CAR spec](https://ipld.io/specs/transport/car/).
 
-## Table of Contents
+Note that there are two major module versions:
 
-- [Install](#install)
-- [Contribute](#contribute)
-- [License](#license)
+* [go-car/v2](v2/) is geared towards reading and writing CARv2 files, and also
+  supports consuming CARv1 files and using CAR files as an IPFS blockstore.
+* go-car v0, in the root directory, just supports reading and writing CARv1 files.
 
+Most users should attempt to use v2, especially for new software.
+
+## Maintainers
+
+[Daniel Martí](https://github.com/mvdan) and [Masih Derkani](https://github.com/masih).
 
 ## Contribute
 

v2/LICENSE.md

@@ -0,0 +1 @@
+../LICENSE.md

v2/blockstore/doc.go

@@ -1,4 +1,4 @@
-// package blockstore implements IPFS blockstore interface backed by a CAR file.
+// package blockstore implements the IPFS blockstore interface backed by a CAR file.
 // This package provides two flavours of blockstore: ReadOnly and ReadWrite.
 //
 // The ReadOnly blockstore provides a read-only random access from a given data payload either in

v2/doc.go

@@ -1,3 +1,8 @@
-// Package car represents the CARv2 implementation.
-// TODO add CARv2 byte structure here.
+// Package car allows inspecting and reading CAR files,
+// described at https://ipld.io/specs/transport/car/.
+// The entire library is geared towards the CARv2 spec,
+// but many of the APIs consuming CAR files also accept CARv1.
+//
+// The blockstore sub-package contains an implementation of the
+// go-ipfs-blockstore interface.
 package car