Needs documentation about playgrounds notebooks and building scripts.

[sonsongithub]

Needs documents about ."How to build playgrounds notebooks" and "Which is the newest one?"

1. some old playgrounds is unnecessary?
2. which one is the newest notebook?
3. Should I run a script in order to build the newest notebook?

[omochi]

I write roughly here temporary.

• playbook/Cat.playgroundbook is unnecessary now. But if i mistaken, some latest code is in it and its not recovered to sources now. Because we are directly edit book last time...

• to build latest ipad book, do this.

$ tool/build-ipad-playbook.rb

this generate playbook/numsw-ipad.playgroundbook

• to build latest xcode playground

$ tool/build-xcode-playbook.rb

this generate playbook/numsw-xcode.playgroundbook

• they are written in ruby 2.2.2

• playbook/ipad is book material.

• playbook/xcode is xcode playground material.

[sonsongithub]

OK. I'll fix them later, at the other branch. Thank you.

[sonsongithub]

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