Fix typos, grammar in the comments and clarify them
diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index 81daaee..d9b37e0 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -1899,8 +1899,8 @@
*
* Enable the TCP and UDP over IPv6/IPv4 networking routines.
*
- * \note This module only works on Unix (including Linux, BSD and OS X) and
- * Windows. For other platforms, you'll want to disable it, and write your
+ * \note This module only works on POSIX/Unix (including Linux, BSD and OS X)
+ * and Windows. For other platforms, you'll want to disable it, and write your
* own networking callbacks to be passed to \c mbedtls_ssl_set_bio().
*
* \note See also our Knowledge Base article about porting to a new
@@ -2275,8 +2275,8 @@
*
* Enable the semi-portable timing interface.
*
- * \note The provided implementation only works on Unix (including Linux, BSD
- * and OS X) and Windows. On other platforms, you can either disable that
+ * \note The provided implementation only works on POSIX/Unix (including Linux,
+ * BSD and OS X) and Windows. On other platforms, you can either disable that
* module and provide your own implementations of the callbacks needed by
* \c mbedtls_ssl_set_timer_cb() for DTLS, or leave it enabled and provide
* your own implementation of the whole module by setting