Remove mixin from docs

doc/api.markdown

@@ -85,11 +85,6 @@ package a module as a directory.
 paths onto it, or at startup with the `NODE_PATH` environmental
 variable (which should be a list of paths, colon separated).
 
-Use `process.mixin()` to include modules into the global namespace.
-
-    process.mixin(GLOBAL, require('./circle'), require('sys'));
-    puts('The area of a circle of radius 4 is ' + area(4));
-
 
 ## Buffers