Update link to brief introduction slides

I redid the formatting of the presentation as a new deck.
This pull request updates the link to point to this new version.

Signed-off-by: David A. Wheeler <[email protected]>

Author: david-a-wheeler

README.md

@@ -91,7 +91,7 @@ Our work is organized into several discrete-yet-related projects that help us ac
 
 ## Related resources
 
-- [A Brief Introduction to Developing Secure Software (short presentation)](https://docs.google.com/presentation/d/1GzLX4CYr4HtXrNF6wyO11hzz9EgwriKhnbvVZ9-LG2E/edit)
+- [A Brief Introduction to Developing Secure Software (short presentation)](https://docs.google.com/presentation/d/12b7Wm6KRp9kd1oV3QVrJpiCWVDexxF8doYZOFOfLy2Y/edit)
 
 ## Past Work/Greatest Hits