Fix typo in first paragraph

es6 & beyond/ch8.md

@@ -1,7 +1,7 @@
 # You Don't Know JS: ES6 & Beyond
 # Chapter 8: Beyond ES6
 
-At the time of this writing, the final draft of ES6 (*ECMAScript 2015*) is shortly headed toward its final official vote of approval by ECMA. But even as ES6 is being finalized, the TC39 committee is already hard at work at on features for ES7/2016 and beyond.
+At the time of this writing, the final draft of ES6 (*ECMAScript 2015*) is shortly headed toward its final official vote of approval by ECMA. But even as ES6 is being finalized, the TC39 committee is already hard at work on features for ES7/2016 and beyond.
 
 As we discussed in Chapter 1, it's expected that the cadence of progress for JS is going to accelerate from updating once every several years to having an official version update once per year (hence the year-based naming). That alone is going to radically change how JS developers learn about and keep up with the language.