Update courses.md

This change is adding the interactive, open-source, community-led SICP version that was adapted into JavaScript. 

This addition seems worthwhile because JavaScript may be a more appealing language to go through SICP with than the original Scheme. In addition, this JavaScript version of SICP was created with the apparent goal of being as close to the original Scheme version as possible:
https://sourceacademy.org/sicpjs/prefaces03

extras/courses.md

@@ -22,6 +22,7 @@ Courses | Duration | Effort
 [Introduction to Programming with MATLAB](https://www.coursera.org/learn/matlab)| - | -
 [Introduction to Functional Programming](https://www.edx.org/course/introduction-functional-programming-delftx-fp101x-0)| 7 weeks | 4-6 hours/week
 [The Structure and Interpretation of Computer Programs (2022, Python)](http://cs61a.org/) | - | -
+[The Structure and Interpretation of Computer Programs (2021, JavaScript)](https://sourceacademy.org/sicpjs/index) | - | -
 [The Structure and Interpretation of Computer Programs (2011, Scheme)](https://romanbird.github.io/sicp/) | - | -
 [Introduction to Haskell](https://www.seas.upenn.edu/~cis194/fall16/) | 14 weeks | 4 hours/week