doc: Fix table format in cheatsheet

Author: brson

doc/complement-cheatsheet.md

@@ -165,12 +165,12 @@ let _ = close(Door::<Closed>(~"front")); // error: mismatched types: expected `m
 
 ## C function signature conversions
 
-Description           | C signature                                  | Equivalent Rust signature
-----------------------|----------------------------------------------|------------------------------------------
-no parameters         | `void foo(void);`                            | `fn foo();`
-return value          | `int foo(void);`                             | `fn foo() -> c_int;`
-function parameters   | `void foo(int x, int y);`                    | `fn foo(x: int, y: int);`
-in-out pointers       | `void foo(const int* in_ptr, int* out_ptr);` | `fn foo(in_ptr: *c_int, out_ptr: *mut c_int);`
+Description            C signature                                    Equivalent Rust signature
+---------------------- ---------------------------------------------- ------------------------------------------
+no parameters          `void foo(void);`                              `fn foo();`
+return value           `int foo(void);`                               `fn foo() -> c_int;`
+function parameters    `void foo(int x, int y);`                      `fn foo(x: int, y: int);`
+in-out pointers        `void foo(const int* in_ptr, int* out_ptr);`   `fn foo(in_ptr: *c_int, out_ptr: *mut c_int);`
 
 Note: The Rust signatures should be wrapped in an `extern "ABI" { ... }` block.