Update Object.group to Object.groupBy (#81)

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/groupBy

README.md

@@ -120,7 +120,7 @@ Built-in Signals enable JS runtimes and DevTools to potentially have improved su
 
 ##### Benefits of a standard library 
 
-In general, JavaScript has had a fairly minimal standard library, but a trend in TC39 has been to make JS more of a "batteries-included" language, with a high-quality, built-in set of functionality available. For example, Temporal is replacing moment.js, and a number of small features, e.g., `Array.prototype.flat` and `Object.group` are replacing many lodash use cases. Benefits include smaller bundle sizes, improved stability and quality, less to learn when joining a new project, and a generally common vocabulary across JS developers.
+In general, JavaScript has had a fairly minimal standard library, but a trend in TC39 has been to make JS more of a "batteries-included" language, with a high-quality, built-in set of functionality available. For example, Temporal is replacing moment.js, and a number of small features, e.g., `Array.prototype.flat` and `Object.groupBy` are replacing many lodash use cases. Benefits include smaller bundle sizes, improved stability and quality, less to learn when joining a new project, and a generally common vocabulary across JS developers.
 
 ##### HTML/DOM Integration (a future possibility)