Update README.md

README.md

@@ -2,14 +2,14 @@ PCP client library
 ===================
 
 PCP client library implements client side of PCP 
-([RFC 6887](http://datatracker.ietf.org/doc/rfc6887/)) and 
-NATPMP([RFC 6886](http://tools.ietf.org/html/rfc6886)) protocols. 
-Switch to NATPMP is done automatically by version negotiation. This library 
+([RFC 6887](https://datatracker.ietf.org/doc/rfc6887/)) and 
+NAT-PMP ([RFC 6886](https://datatracker.ietf.org/doc/rfc6886/)) protocols. 
+Switch to NAT-PMP is done automatically by version negotiation. This library 
 enables any network application to manage network edge device (e.g. to create
 NAT mapping or ask router for specific flow treatment).
 
 Supported platforms are 
-Linux, MS Windows (Vista and later), OS X.
+Linux, Microsoft Windows (Vista and later), macOS.
 
 ### Components ###
 
@@ -20,4 +20,3 @@ Linux, MS Windows (Vista and later), OS X.
 
 Build instructions are located in INSTALL.md file. More information about
 components are in each subdirectory's README.md file.
-