Installation and first use should be smoother

[vtamara]

After installling and running on adJ 7.1 and Ubuntu 21.10 (see https://github.com/vtamara/react-webpack-rails-tutorial/wiki/Using-on-adJ-(distribution-of-OpenBSD)-7.1a1 and https://github.com/vtamara/react-webpack-rails-tutorial/wiki/Using-on-Ubuntu-21.10 ) I have some suggestions to make the installation smoother:

• Documentation of the installation steps should be precise
• Documentation and code should be more portable.
• IMHO, avoid unncessary installation steps, e.g running foreman requires the addtional step of installing globally the gem foreman, better bundle exec foreman
• Use the simplest tools that help to understand the concepts of react_on_rails, for example node instead of mini_racer (due to difficulties with versions of libv8, ruby-libv8, mini_racer and different operating systems --even on Ubuntu--, the gem mini_racer uses to be problematic, although it is good for production code where speed is priority as could be stated as commentary in the Gemfile).
• In case that a user forks, changes and commits his/her changes to the repository, that he/she will not publish the user or passwords by mistake in config/database.yml
• Updated gems and npm packages

[vtamara]

I will be sending a PR to solve this.

[vtamara]

PR sent yesterday: https://github.com/shakacode/react-webpack-rails-tutorial/pull/496