Update name and website of Bookmark Archiver

The name of this project was officially changed from **Bookmark Archiver** to **ArchiveBox** in commit [#108](https://github.com/pirate/ArchiveBox/issues/108). Its official website was likewise changed from https://pirate.github.io/bookmark-archiver to https://archivebox.io/. This commit updates the README.md file to reflect these changes.

README.md

@@ -138,8 +138,8 @@ Some [Content Management System](#content-management-systems-cms) solutions also
 
 - [Access to Memory (AtoM)](https://www.accesstomemory.org/) - Web-based, open source application for standards-based archival description and access in a multilingual, multi-repository environment. ([Demo](https://demo.accesstomemory.org/), [Source Code](https://github.com/artefactual/atom)) `AGPL-3.0-only` `PHP`
 - [Archivematica](https://www.archivematica.org/) - Mature digital preservation system designed to maintain standards-based, long-term access to collections of digital objects. ([Demo](http://sandbox.archivematica.org/administration/accounts/login/), [Source Code](https://github.com/artefactual/archivematica)) `AGPL-3.0-only` `Python`
+- [ArchiveBox](https://archivebox.io/) - Self-hosted "wayback machine" that creates HTML & screenshot archives of sites from your bookmarks, browsing history, RSS feeds, or other sources. ([Demo](https://archive.sweeting.me), [Source Code](https://github.com/pirate/bookmark-archiver)) `MIT` `Python`
 - [ArchivesSpace](https://archivesspace.org/) - Archives information management application for managing and providing Web access to archives, manuscripts and digital objects. ([Demo](https://archivesspace.org/application/demo/), [Source Code](https://github.com/archivesspace/archivesspace)) `ECL-2.0` `Ruby`
-- [Bookmark Archiver](https://pirate.github.io/bookmark-archiver) - Self-hosted "wayback machine" that creates HTML & screenshot archives of sites from your bookmarks, browsing history, RSS feeds, or other sources. ([Demo](https://archive.sweeting.me), [Source Code](https://github.com/pirate/bookmark-archiver)) `MIT` `Python`
 - [Collective Access: Providence](http://collectiveaccess.org/) - Highly configurable Web-based framework for management, description, and discovery of digital and physical collections supporting a variety of metadata standards, data types, and media formats. ([Source Code](https://github.com/collectiveaccess/providence)) `GPL-3.0-only` `PHP` 
 
 ## Automation