docs: update download link for binaries

The tag name will be updated and it is indeed better to list all releases.

Signed-off-by: Claudio André <dev@claudioandre.slmail.me>

README.md

@@ -1,5 +1,5 @@
 [![Circle CI](https://circleci.com/gh/openwall/john/tree/bleeding-jumbo.svg?style=shield)](https://circleci.com/gh/openwall/john/tree/bleeding-jumbo)
-[![Downloads](https://img.shields.io/badge/Download-Windows%20Build-blue.svg)](https://github.com/openwall/john-packages/releases/tag/jumbo-dev)
+[![Downloads](https://img.shields.io/badge/Download-Windows%20Build-blue.svg)](https://github.com/openwall/john-packages/releases)
 [![License](https://img.shields.io/badge/License-GPL%20v2%2B-blue.svg)](https://github.com/openwall/john/blob/bleeding-jumbo/doc/LICENSE)
 ![GitHub commit activity](https://img.shields.io/github/commit-activity/m/openwall/john?color=yellow)
 ![GitHub commits since tagged version](https://img.shields.io/github/commits-since/openwall/john/1.9.0-Jumbo-1?color=brown)