Style fixes on the About page. Fixes jquery#279.

* Oxford commas.
* Period after second bullet point sentence.
* Em dashes instead of double-hyphens.
* Fix typo: "who need the right away" -> "who need them right away".

Author: Markus Amalthea Magnuson

page/about.md

@@ -1,6 +1,6 @@
 ---
 title: About This Site
-customFields: 
+customFields:
   -
     key: "is_chapter"
     value: 0
@@ -15,7 +15,7 @@ how to do exactly what they need to do.
 
 However, API documentation alone cannot serve as a guide to solving problems
 and fostering a true understanding of web development. Over the years, an
-ecosystem of blog posts, books, support forums and channels has grown to help
+ecosystem of blog posts, books, support forums, and channels has grown to help
 cover the **hows** and **whys** of developing with jQuery, as well as explaining
 best practices, techniques, and workarounds for common problems. This type of
 documentation has been invaluable resource for millions of people, but the
@@ -29,8 +29,8 @@ curate this information in order to provide this crucial "narrative
 documentation" to our community and serve the following goals:
 
 1. Provide our **users** with a digestible reference on all aspects of using jQuery, from the basics of getting started and performing common tasks to more advanced topics like approaches to structuring code and where jQuery fits into modern web application development.
-2. Provide our **contributors** a central, open place to collaborate and provide a dependable, highly sharable resource that will improve our users' support experiences
-3. Foster an environment by which users are encouraged to become contributors and build the skills to help them work on jQuery -- or any other open source project!
+2. Provide our **contributors** a central, open place to collaborate and provide a dependable, highly sharable resource that will improve our users' support experiences.
+3. Foster an environment by which users are encouraged to become contributors and build the skills to help them work on jQuery — or any other open source project!
 
 In order to achieve these goals, all of [this site's content is maintained
 publicly on GitHub](http://github.com/jquery/learn.jquery.com) and is licensed
@@ -53,18 +53,18 @@ for some sort of "learning center."
 The second is [docs.jquery.com](http://docs.jquery.com), that erstwhile
 chestnut still living out its final days before it will be shut down in early
 2013. Since we've moved the API documentation for jQuery Core off that domain,
-we needed a place that could serve a similar need -- documentation (that anyone
-can contribute to) that gets into the "how-to" and FAQs -- without clumsy
+we needed a place that could serve a similar need — documentation (that anyone
+can contribute to) that gets into the "how-to" and FAQs — without clumsy
 barriers to entry like finding the right person to set you up with a special
 wiki account and forcing all authoring into a `textarea`.
 
-<h2><a name="beta">About the Beta</a></h2> 
+<h2><a name="beta">About the Beta</a></h2>
 
 Though this resource will never truly be "done," the current version of this
 site should still be considered something of a preview. We still have a number
 of improvements we want to make to the content, user experience, and site build
 before we're ready to call it a "final release." At the same time, however,
 it's important for us to open the doors now so we can begin providing better
-docs to people who need the right away and spread the word about this effort.
+docs to people who need them right away and spread the word about this effort.
 If you're interested in helping us reach the finish line, we invite you to
 please read more about how [you can get involved with contributing](/contributing)!