add link to cortex-m-rtfm on crates.io

Author: japaric

content/2019-02-20-newsletter-15.md

@@ -147,8 +147,9 @@ For a bit more of detail you can check the [logs] and [minutes] from two meeting
 
 If you have an embedded project or blog post you would like to have featured in the Embedded WG Newsletter, make sure to add it to [the next newsletter], we would love to show it off!
 
-- Version v0.4.1 of Real Time For the Masses (RTFM), a concurrency framework for building real time systems, has been released! This version [fixes a soundness hole][rtfm#140] and includes a [Russian translation] of the RTFM book.
+- Version v0.4.1 of [Real Time For the Masses][rtfm] (RTFM), a concurrency framework for building real time systems, has been released! This version [fixes a soundness hole][rtfm#140] and includes a [Russian translation] of the RTFM book.
 
+[rtfm]: https://crates.io/crates/cortex-m-rtfm
 [rtfm#140]: https://github.com/japaric/cortex-m-rtfm/pull/140
 [Russian translation]: https://japaric.github.io/cortex-m-rtfm/book/ru/index.html