Revise README for improved clarity and links

Updated links and text for clarity in README.

Author: mulle-nat

README.md

@@ -10,15 +10,12 @@ is the most convenient way to install [mulle-objc](//github.com/mulle-objc)
 and [mulle-sde](//github.com/mulle-sde).
 
 Installing foundation-developer is also the main way to install all the other
-developer packages, like mulle-objc-developer or mulle-core-developer.
+developer packages, like  [mulle-objc-developer](//github.com/mulle-objc/mulle-objc-developer).
 
-See [The mulle-objc Community](//mulle-objc.github.io) for more information about
+See the [mulle-objc](//mulle-objc.github.io) site for more information about
 *mulle-objc* and *mulle-sde*.
 
 
-
-
-
 ## Usage
 
 The following examples show how to use the *MulleFoundation* with the