chore(toh-5): Fix broken link to master style in TOH pt5 (#3201)

Author: robshep

public/docs/ts/latest/tutorial/toh-pt5.jade

@@ -881,7 +881,7 @@ block style-urls
 
 +makeExcerpt('src/styles.css (excerpt)', 'toh')
 
-- var styles_css = 'https://raw.githubusercontent.com/angular/angular.io/master/public/docs/_examples/_boilerplate/styles.css'
+- var styles_css = 'https://raw.githubusercontent.com/angular/angular.io/master/public/docs/_examples/_boilerplate/src/styles.css'
 
 :marked
   Create the file <span ngio-ex>styles.css</span>, if it doesn't exist already.