add existing documentation

doc/protocols/rosetta/io/Directory.rp

@@ -0,0 +1,16 @@
+
+mod rosetta.io;
+
+protocol Directory;
+
+struct Entry {
+	char[64] name;
+}
+
+msg Open
+  -> string path, i32 flags;
+  <- i32 status;
+
+msg GetEntries
+  -> i32 count;
+  <- 

doc/protocols/rosetta/io/File.rp

@@ -0,0 +1,12 @@
+
+mod rosetta.io;
+
+protocol File:
+
+msg Read
+  -> u32 count;
+  <- i32 status, char[] data;
+
+msg Write
+  -> char[] data;
+  <- i32 status;