Update environment documentation

README.md

@@ -63,9 +63,9 @@ In Kemal, a route is an HTTP method paired with a URL-matching pattern. Each rou
   end  
 ```
 
-## Context
+## Environment
 
-Accessing the request environment (query params, body, headers e.g) is super easy. You can use the context returned from the block:
+Accessing the environment (query params, body, content_type, headers, status_code) is super easy. You can use the environment returned from the block:
 
 ```ruby
   # Matches /hello/kemal
@@ -79,18 +79,19 @@ Accessing the request environment (query params, body, headers e.g) is super eas
     width = env.params["width"]
     height = env.params["height"]
   end
-```
 
-## Content Type
-Kemal uses *text/html* as the default content type. You can change it via the context.
-
-```ruby
   # Set the content as application/json and return JSON
   get "/user.json" do |env|
     kemal = {name: "Kemal", language: "Crystal"}
-    env.set_content_type "application/json"
+    env.content_type = "application/json"
     kemal.to_json
   end
+  
+  # Add headers to your response
+  get "/headers" do |env|
+    env.add_header "Accept-Language", "tr"
+    env.add_header "Authorization", "Token 12345"
+  end
 ```
 
 ## Thanks