Fix link for save code now

Resolves #2

chapters/2.Accessibility_preservation.md

@@ -7,7 +7,7 @@ To ensure accessibility and preservation, researchers and software engineers are
 ### RSMD-2.1
 **Essential ☆☆☆**
 
-Archive the source code repository in the <span style="text-decoration:underline;">universal source code archive</span>, [Software Heritage](https://archive.softwareheritage.org/), using the [save code now,](save.softwareheritage.org) to ensure long-term access to the full development history. 
+Archive the source code repository in the <span style="text-decoration:underline;">universal source code archive</span>, [Software Heritage](https://archive.softwareheritage.org/), using the [save code now,](https://save.softwareheritage.org) to ensure long-term access to the full development history. 
 
 * This method can be used for software at any level of maturity when software is publicly available.