README.md in browser-2.7.1 vs README.md in browser-3.0.0

@@ -56,11 +56,12 @@
 
 # Get bot info
 browser.bot.name
 browser.bot.search_engine?
 browser.bot?
-Browser::Bot.why?(ua) # shows which user agent was the offender
+browser.bot.why? # shows which matcher detected this user agent as a bot.
+Browser::Bot.why?(ua)
 
 # Get device info
 browser.device
 browser.device.id
 browser.device.name
@@ -144,25 +145,25 @@
 - For a list of device detections, check [lib/browser/device.rb](https://github.com/fnando/browser/blob/master/lib/browser/device.rb)
 - For a list of bot detections, check [bots.yml](https://github.com/fnando/browser/blob/master/bots.yml)
 
 ### What defines a modern browser?
 
-The current rules that define a modern browser are pretty loose:
+The current rules that define a modern browser are pretty loose.
 
-* Webkit
-* IE9+
-* Microsoft Edge
-* Firefox 17+
-* Firefox Tablet 14+
-* Opera 12+
+* Chrome 65+
+* Safari 10+
+* Firefox 52+
+* IE11+
+* Microsoft Edge 39+
+* Opera 50+
 
 You can define your own rules. A rule must be a proc/lambda or any object that implements the method === and accepts the browser object. To redefine all rules, clear the existing rules before adding your own.
 
 ```ruby
-# Only Chrome Canary is considered modern.
+# Only Google Chrome 79+ is considered modern.
 Browser.modern_rules.clear
-Browser.modern_rules << -> b { b.chrome? && b.version.to_i >= 37 }
+Browser.modern_rules << -> b { b.chrome? && b.version.to_i >= 79 }
 ```
 
 ### Rails integration
 
 Just add it to the Gemfile.
@@ -211,11 +212,11 @@
 
 language.name
 #=> "English/United States"
 ```
 
-Result is always sorted in quality order from highest -> lowest. As per the HTTP spec:
+Result is always sorted in quality order from highest to lowest. As per the HTTP spec:
 
 - omitting the quality value implies 1.0.
 - quality value equal to zero means that is not accepted by the client.
 
 ### Internet Explorer
@@ -264,13 +265,32 @@
 #=> true
 ```
 
 ### Bots
 
-Browser used to detect empty user agents as bots, but this behavior has changed. If you want to bring this detection back, you can activate it through the following call:
+The bot detection is quite aggressive. Anything that matches at least one of the following requirements will be considered a bot.
 
+- Empty user agent string
+- User agent that matches `/crawl|fetch|search|monitoring|spider|bot/`
+- Any known bot listed under [bots.yml](https://github.com/fnando/browser/blob/master/bots.yml)
+
+To add custom matchers, you can add a callable object to `Browser::Bot.matchers`. The following example matches everything that has a `externalhit` substring on it. The bot name will always be `General Bot`.
+
 ```ruby
-Browser::Bot.detect_empty_ua!
+Browser::Bot.matchers << ->(ua, _browser) { ua =~ /externalhit/i }
+```
+
+To clear all matchers, including the ones that are bundled, use `Browser::Bot.matchers.clear`. You can re-add built-in matchers by doing the following:
+
+```ruby
+Browser::Bot.matchers += Browser::Bot.default_matchers
+```
+
+To restore v2's bot detection, remove the following matchers:
+
+```ruby
+Browser::Bot.matchers.delete(Browser::Bot::KeywordMatcher)
+Browser::Bot.matchers.delete(Browser::Bot::EmptyUserAgentMatcher)
 ```
 
 ### Middleware
 
 You can use the `Browser::Middleware` to redirect user agents.