[Changelog] Update wording of Podfile sources entry

Thanks @orta

CHANGELOG.md

@@ -6,11 +6,11 @@ To install or update CocoaPods see this [guide](http://docs.cocoapods.org/guides
 
 ##### Breaking
 
-* Add support for loading podspecs from specific spec-repos _only_,
-  a.k.a. ‘sources’. By default, when not specifying any specific sources in your
-  Podfile, all source repos will be used, as has always been the case.
-  This implicit use of sources is, however, now deprecated.
-  However, once you specify specific sources, **no** repos wil be included by
+* Add support for loading podspecs from *only* specific spec-repos via
+  `sources`. By default, when there are no sources specified in a Podfile all
+  source repos will be used. This has always been the case.
+  However, this implicit use of sources is now deprecated.
+  Once you specify specific sources, **no** repos wil be included by
   default. For example:
 
         source 'https://banana.com/corp/private-spec-repo.git'