Fix arity of alias!/1

getting-started/meta/macros.markdown

@@ -179,7 +179,7 @@ Sample.quoted #=> {:x, [line: 3], Sample}
 
 Notice that the third element in the quoted variable is the atom `Sample`, instead of `nil`, which marks the variable as coming from the `Sample` module. Therefore, Elixir considers these two variables as coming from different contexts and handles them accordingly.
 
-Elixir provides similar mechanisms for imports and aliases too. This guarantees that a macro will behave as specified by its source module rather than conflicting with the target module where the macro is expanded. Hygiene can be bypassed under specific situations by using macros like `var!/2` and `alias!/2`, although one must be careful when using those as they directly change the user environment.
+Elixir provides similar mechanisms for imports and aliases too. This guarantees that a macro will behave as specified by its source module rather than conflicting with the target module where the macro is expanded. Hygiene can be bypassed under specific situations by using macros like `var!/2` and `alias!/1`, although one must be careful when using those as they directly change the user environment.
 
 Sometimes variable names might be dynamically created. In such cases, `Macro.var/2` can be used to define new variables: