Testing Cleanup

Thought I'd suggest some edits based on grammar and some spelling mistakes considering how useful this Bot has been for the project I'm working on. Feel free to ignore if it's not needed.

README.md

@@ -395,11 +395,11 @@ Telegram::Bot::UpdatesPoller.start(bot, controller_class)
 
 ### Testing
 
-There is `Telegram::Bot::ClientStub` class to stub client for tests.
-Instead of performing API requests it stores them in `requests` hash.
+There is a `Telegram::Bot::ClientStub` class to stub client for tests.
+Instead of performing API requests it stores them in a `requests` hash.
 
 To stub all possible clients use `Telegram::Bot::ClientStub.stub_all!` before
-initializing clients. Here is template for RSpec:
+initializing clients. Here is a template for RSpec:
 
 ```ruby
 # environments/test.rb
@@ -418,23 +418,23 @@ end
 ```
 
 RSpec contexts and helpers are included automatically for groups and examples with matching
-tags. In RSpec < 3.4 it's require to use `include_context` explicitly.
+tags. In RSpec < 3.4 you're required to use `include_context` explicitly.
 See [list of available helpers](https://github.com/telegram-bot-rb/telegram-bot/tree/master/lib/telegram/bot/rspec)
 for details.
 
 There are 3 types of integration tests:
 
-- `:rails` - for testing bot in webhooks-mode in Rails application.
+- `:rails` - For testing bot in webhooks-mode in Rails application.
   It simulates webhook requests like request specs, POSTing data to controller's endpoint.
-- `:rack` - for testing bot in webhooks-mode in non-Rails application.
-  It uses `rack-test` gem to POST requests to bot's endpoint.
-- `:poller` - calls `.dispatch` directly on controller class.
+- `:rack` - For testing bot in webhooks-mode in non-Rails application.
+  It uses the `rack-test` gem to POST requests to bot's endpoint.
+- `:poller` - Calls `.dispatch` directly on controller class.
 
 Pick the appropriate one, then require `telegram/bot/rspec/integration/#{type}`
 and mark spec group with tag `telegram_bot: type`. See configuration options
 for each type in `telegram/bot/rspec/integration/`.
 
-Here is example for Rails app:
+Here is an example test for a Rails app:
 
 ```ruby
 # spec/requests/telegram_webhooks_spec.rb
@@ -453,7 +453,7 @@ RSpec.describe TelegramWebhooksController, telegram_bot: :rails do
     # The most basic one is #make_telegram_request(bot, endpoint, params_matcher)
     expect { dispatch_command(:start) }.
       to make_telegram_request(bot, :sendMessage, hash_including(text: 'msg text'))
-    # There are some shortcuts for ba
+    # There are some shortcuts for basic commands and responses.
     expect { send_message('Hi') }.to send_telegram_message(bot, /msg regexp/, some: :option)
   end
 
@@ -474,12 +474,12 @@ RSpec.describe TelegramWebhooksController, telegram_bot: :rails do
 end
 ```
 
-There is context for testing bot controller in the way similar to Rails controller tests.
-It's supposed to be low-level alternative for request specs. Among the differencies is
-that controller tests use single controller instance for all dispatches in single exaple,
+There is a context for testing bot controller in the way similar to Rails controller tests.
+It's supposed to be a low-level alternative for request specs. Among the differencies is
+that controller tests use a single controller instance for all dispatches in a specific example,
 session is stubbed (does not use configured store engine), and update is not serialized
-so it support mocks. This can be useful for unit testing, but should not be considered as
-default way to test bot.
+so it also supports mocks. This can be useful for unit testing, but should not be used as
+the default way to test the bot.
 
 ```ruby
 require 'telegram/bot/updates_controller/rspec_helpers'