feat: update first chapters

content.en/_index.md

@@ -8,15 +8,21 @@ type: docs
 ## Learn Test-Driven Development with Ruby
 
 * Explore the Ruby language by writing tests.
-* **Get a grounding with TDD**.
-    * Ruby is a good language for learning TDD because it is a simple language to learn and testing is built-in.
+* Ruby is a good language for learning TDD because it is a simple language to learn and testing is really simple.
 * Be confident that you'll be able to start writing robust, well-tested systems in Ruby.
 
 ## Who this is for
 
 * People who are interested in picking up Ruby.
 * People who already know some Ruby, but want to explore testing more.
 
+## What you'll need
+* A computer!.
+* Installed [Ruby](/docs/before-start/install-ruby/).
+* A text editor.
+* Some experience with programming.
+* Comfortable using the terminal.
+
 ## Feedback
 
 * Add issues/submit PRs [here](https://github.com/pmareke/learn-ruby-with-tests) or [tweet me @pmareke](https://twitter.com/pmareke)

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

@@ -1,6 +1,56 @@
 ---
 title: Install Minitest
-weight: 3
+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.
+
+## How to install Minitest
+
+```sh
+# Gemfile
+source "https://rubygems.org"
+
+gem "minitest"
+```
+
+```sh
+bundle install
+```
+
+## Validate Minitest is installed
+
+Once you have Minitest installed you need to create
+a new file called `test_foo.rb` with the following code
+(*right now don't care about it!*):
+
+```ruby
+require "minitest/autorun"
+
+class TestFoo < Minitest::Test
+  def test_foo
+    assert_equal 1, 1
+  end
+end
+```
+Save the file and run the following command in the terminal:
+
+```sh
+ruby test_foo.rb
+```
+
+You should see something like these results:
+
+```sh
+Run options: --seed 6109
+
+# Running:
+
+.
+
+Finished in 0.000829s, 1206.0617 runs/s, 1206.0617 assertions/s.
+1 runs, 1 assertions, 0 failures, 0 errors, 0 skips
+```

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

@@ -4,3 +4,32 @@ weight: 2
 ---
 
 # Install Ruby
+
+## How to install Ruby
+
+There a couple of ways to install Ruby in your computer:
+
+* You can go to the official [page](https://www.ruby-lang.org/en/documentation/installation/#package-management-systems)
+and follow the given instructions for your operation system.
+* You can use the Ruby Version Manager [RVM](http://rvm.io/rvm/install#basic-install).
+
+## Validate Ruby is installed
+
+Once you have Ruby installed you should be able to run the following command
+in the terminal:
+
+```sh
+ruby -v # => ruby 3.1.2p20 (2022-04-12 revision 4491bb740a) [x86_64-linux]
+```
+
+Also you should be able to open an interactive ruby shell using the following
+command in the terminal:
+
+```sh
+irb
+```
+In which you can run Ruby code like this one:
+
+```sh
+irb(main):001> 1 + 1 # => 2
+```

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

@@ -0,0 +1,23 @@
+---
+title: Prepare the project
+weight: 3
+---
+
+# Prepare the project for this book
+
+## Create the folder for the chapters and its tests
+
+```sh
+mkdir tests src
+```
+
+## Create a new Ruby project
+
+```sh
+bundle init
+```
+
+```sh
+# Gemfile
+source "https://rubygems.org"
+```