Proposal: Add a File I/O chapter (from vol 2) to UPBE

[dmitrizagidulin]

Currently, a reader who finishes PBE has a programming language with no way to get data in or out of it. They can't do the most basic operations -- read some lines from a data file. (Even though they know how to create basic GUI desktop applications at this point, which is an advanced topic).

I strongly suggest that we add a basic File I/O chapter to UPBE (or better yet, move Chapter 3: Files with FileSystem from Deep Into Pharo to this book).

Reasons to have a File IO chapter in UPBE:

1. It is crucial beginner functionality. Many of the other chapters in this book are useless if the developer has no data to operate on.
2. It addresses a common misconception about Smalltalk/Pharo, which is that it is "isolated" or "doesn't play well with others". As long as we show that you can easily work with files in Pharo (or use a web client to interact with APIs), it means that Pharo has as much inter-op as any other language.

[kilon]

I think we need a diffirent chapter. We should not forget this is a "by Example" book so I would like to see practical examples that newcomers can use out of the box. So yes to a chapter, but I would like a chapter that is more beginner orientated.