Non-developer README contribution

[SpaghettiThots]

I have written a clear, easy-to-comprehend introduction for bash.academy. Having gone through it to an extent, I believe this introduction, free of complex technical terms, will swiftly and thoroughly inform anyone about the use-cases, merit, and advantages, including the celebrated features, of bash.academy. Bash Academy deserves the maximum publicity it can get but that starts when whoever comes in contact with it really gets it . This will make it easier for them to share at user groups, dev schools and in curated content online. This is the first of a few contributions I plan to make to this awesome project.