document seek/tell somewhat

also slurp is deprecated

lib/Type/IO/Handle.pod

@@ -67,11 +67,32 @@ Binary writing; writes C<$buf> to the filehandle.
 
 =head2 method seek
 
+     method seek(IO::Handle:D: Int:D $offset, Int:D $whence)
+
+Move the file pointer (that is the position at which any subsequent read
+or write operations will begin,) to the byte position specified by
+C<$offset> relative to the location specified by C<$whence> which may be
+one of:
+
+=item 0
+
+The beginning of the file.
+
+=item 1
+
+The current position in the file.
+
+=item 2
+
+The end of the file.
+
 =head2 method tell
 
-=head2 method slurp
+    method tell(IO::Handle:D: --> Int)
+
+Return the current position of the file pointer in bytes.
 
-=head2 method spurt
+=head2 method slurp-rest
 
 =head2 method close