Add link to slides for racy jgit lightning talk

Change-Id: Id9676503709b1eb71b6d15ca7da513953d1f84cf
diff --git a/lightning-talks/jgit-racy-read.md b/lightning-talks/jgit-racy-read.md
index ee4c13c..8064391 100644
--- a/lightning-talks/jgit-racy-read.md
+++ b/lightning-talks/jgit-racy-read.md
@@ -3,4 +3,6 @@
 Git uses file meta-data to avoid it has to read file content for detecting modifications.
 This seems a simple idea but getting the Java implementation in JGit right was a lengthy endeavour.
 
+[Slides](https://speakerdeck.com/msohn/racy-jgit-a-short-history-of-time)
+
 *[Matthias Sohn, Gerrit Contributor and Community Manager](../speakers.md#msohn)*