Update explanation about offset method

Author: therustmonk

src/doc/nomicon/safe-unsafe-meaning.md

@@ -41,8 +41,8 @@ Some examples of unsafe functions:
 
 * `slice::get_unchecked` will perform unchecked indexing, allowing memory
   safety to be freely violated.
-* `ptr::offset` is an intrinsic that invokes Undefined Behavior if it is
-  not "in bounds" as defined by LLVM.
+* every raw pointer to sized type has intrinsic `offset` method that invokes
+  Undefined Behaviour if it is not "in bounds" as defined by LLVM.
 * `mem::transmute` reinterprets some value as having the given type,
   bypassing type safety in arbitrary ways. (see [conversions] for details)
 * All FFI functions are `unsafe` because they can do arbitrary things.