feat: update first chapters

content.en/docs/before-start/install-minitest.md

@@ -5,26 +5,32 @@ weight: 4
 
 # Install Minitest
 
-For this book we're going to use [Minitest](https://github.com/minitest/minitest),
-this testing tool was added to Ruby’s standard library.
+For this book we're going to use [Minitest](https://github.com/minitest/minitest) 
+as the testing framerwork. There are another alternatives like `RSpec` but for the
+sake of simplicity I prefer to use Minitest.
 
 ## How to install Minitest
 
+In order to add a new library in our project we just need to add them in the `Gemfile` file:
+
 ```sh
 # Gemfile
 source "https://rubygems.org"
 
 gem "minitest"
 ```
 
+After that we need to install it using the following command:
+
 ```sh
 bundle install
 ```
+If everything works fine now we're in a position to create our first test.
 
 ## Validate Minitest is installed
 
 Once you have Minitest installed you need to create
-a new file called `test_foo.rb` with the following code
+a new file called `test_foo.rb` inside the `src` folder with the following code
 (*right now don't care about it!*):
 
 ```ruby
@@ -39,7 +45,7 @@ end
 Save the file and run the following command in the terminal:
 
 ```sh
-ruby test_foo.rb
+ruby tests/test_foo.rb
 ```
 
 You should see something like these results:

content.en/docs/before-start/prepare-the-book.md

@@ -5,19 +5,35 @@ weight: 3
 
 # Prepare the project for this book
 
+Once we have Ruby installed we need to create the folders
+structure in which weŕe going to write the code for each
+chapter.
+
+
 ## Create the folder for the chapters and its tests
 
+To do so, we need to create a couple of folders with the 
+following command:
+
 ```sh
 mkdir tests src
 ```
-
 ## Create a new Ruby project
 
+After that we're in position of creating the project using Bundler.
+
+To do it, just run the following command in the terminal:
+
 ```sh
 bundle init
 ```
+This command will create a new file called `Gemfile` in which we're 
+going to add in the future all the dependecies (like `minitest`).
 
 ```sh
-# Gemfile
+# frozen_string_literal: true
+
 source "https://rubygems.org"
+
+# gem "rails"
 ```

examples/Gemfile

@@ -0,0 +1,5 @@
+# frozen_string_literal: true
+
+source "https://rubygems.org"
+
+# gem "rails"

examples/tests/test_foo.rb

@@ -0,0 +1,7 @@
+require "minitest/autorun"
+
+class TestFoo < Minitest::Test
+  def test_foo
+    assert_equal 1, 1
+  end
+end