README: Add link to MANPAGE

MANPAGE.md

@@ -5,7 +5,7 @@
 NAME
 ====
 
-gocryptfs - mount and encrypted directory
+gocryptfs - mount an encrypted directory
 
 SYNOPSIS
 ========

README.md

@@ -30,6 +30,8 @@ Install
 Use
 ---
 
+Quickstart:
+
 	$ mkdir cipher plain
 	$ $GOPATH/bin/gocryptfs --init cipher
 	  [...]
@@ -42,6 +44,8 @@ Use
 	  -rw-rw-r--. 1 user  user  233  7. Okt 23:23 gocryptfs.conf
 	$ fusermount -u plain
 
+See [MANPAGE.md](MANPAGE.md) for a description of available options.
+
 Storage Overhead
 ----------------