Radare2 is documented

Some miscreants are saying that radare2 is not documented, this is wrong. The Book The “radare book” was released together with radare 1.0, several years ago, so some of the examples/features may not be compatible with radare2. You can read it online or download the PDF. Recently, our tester in chief, maijin, started a project to update the radare book to create the radare2 book; feel free to contribute.