Update trinket_m0_haxpress.md

Changed link to archived version as suggested. Thanks.

Author: Timeline8

_board/trinket_m0_haxpress.md

@@ -4,7 +4,7 @@ board_id: "trinket_m0_haxpress"
 title: "Trinket M0 Haxpress Download"
 name: "Trinket M0 Haxpress"
 manufacturer: "Dave Astels"
-board_url:
+board_url: https://web.archive.org/web/20210727135908/http://daveastels.com/trinket-m0-express-hack.html
 board_image: "trinket_m0_haxpress.jpg"
 date_added: 2019-03-19
 family: atmel-samd
@@ -16,4 +16,4 @@ features:
 This is a [Trinket M0]({{ "/board/trinket_m0/" | relative_url }}) that has been had a SPI flash
 chip bodged on by Dave Astels. It is not available for purchase.
 
-It was documented as a DIY project [DEAD LINK](http://daveastels.com/trinket-m0-express-hack.html).
+It was documented as a DIY project [Archived Version; original page is no longer online](https://web.archive.org/web/20210727135908/http://daveastels.com/trinket-m0-express-hack.html).