update guide docs for new middleware style

docs/guide.md

@@ -8,13 +8,11 @@
   `X-Response-Time` header field the middleware would look like the following:
 
 ```js
-function responseTime(next){
+function *responseTime(next){
-  return function *(){
   var start = new Date;
   yield next;
   var ms = new Date - start;
   this.set('X-Response-Time', ms + 'ms');
-  }
 }
 
 app.use(responseTime);
@@ -23,13 +21,11 @@ app.use(responseTime);
   Here's another way to write the same thing, inline:
 
 ```js
-app.use(function(next){
+app.use(function *(next){
-  return function *(){
   var start = new Date;
   yield next;
   var ms = new Date - start;
   this.set('X-Response-Time', ms + 'ms');
-  }
 });
 ```
 
@@ -63,20 +59,9 @@ to this behaviour.
  For example this would be fine:
 
 ```js
-app.use(function(){
+app.use(function *response(){
-  return function *response(){
   if ('/' != this.url) return;
   this.body = 'Hello World';
-  }
-});
-```
-
-  It's important to note that not all middleware will need to conform, the best example of this
-  is a router, which are typically always acting as end-points, or downstream middleware:
-
-````js
-app.use(get('/', function *(){
-  this.body = 'Hello World';
 });
 ```
 
@@ -101,8 +86,7 @@ app.use(get('/', function *(){
 function logger(format){
   format = format || ':method ":url"';
 
-  return function(next){
+  return function *(next){
-    return function *(){
     var str = format
       .replace(':method', this.method)
       .replace(':url', this.url);
@@ -111,7 +95,6 @@ function logger(format){
     
     yield next;
   }
-  }
 }
 
 app.use(logger());
@@ -125,10 +108,8 @@ app.use(logger(':method :url'));
 
 ```js
 function logger(format){
-  return function(next){
+  return function *logger(next){
-    return function *logger(){
+
-      // ^-- name this guy
-    }
   }
 }
 ```
@@ -143,8 +124,7 @@ function logger(format){
 ```js
 var fs = require('co-fs');
 
-app.use(function(){
+app.use(function *(){
-  return function *(){
   var paths = yield fs.readdir('docs');
 
   var files = yield paths.map(function(path){
@@ -153,7 +133,6 @@ app.use(function(){
 
   this.type = 'markdown';
   this.body = files.join('');
-  }
 });
 ```