Easier browser instructions

Learned this trick from @rauchg. much easier and doesn't require a globally exposed debug.

Readme.md

@@ -83,19 +83,13 @@ Then, run the program to be debugged as usual.
 
 ## Browser support
 
-  Debug works in the browser as well, currently persisted by `localStorage`. Consider the situation shown below where you have `worker:a` and `worker:b`, and wish to debug both. Somewhere in the code on your page, include:
+  Debug works in the browser as well, currently persisted by `localStorage`. Consider the situation shown below where you have `worker:a` and `worker:b`, and wish to debug both. You can enable this using `localStorage.debug`:
 
 ```js
-window.myDebug = require("debug");
+localStorage.debug = 'worker:*'
 ```
 
-  ("debug" is a global object in the browser so we give this object a different name.) When your page is open in the browser, type the following in the console:
-
-```js
-myDebug.enable("worker:*")
-```
-
-  Refresh the page. Debug output will continue to be sent to the console until it is disabled by typing `myDebug.disable()` in the console.
+And then refresh the page.
 
 ```js
 a = debug('worker:a');