Update authors field in mode.properties

Replaces markdown link with plain text for the authors field in p5.js mode.properties to make sure the foundation icon shows up.

Author: Stefterv

p5js/library/mode.properties

@@ -1,6 +1,6 @@
 name=p5.js Mode (experimental)
 category=Unknown
-authors=[The Processing Foundation](https://processingfoundation.org/)
+authors=The Processing Foundation
 url=https://github.com/processing/processing-p5.js-mode
 sentence=create p5.js sketches within Processing using the Electron framework
 paragraph=