Fix documentation example in the book

[ollie27]

The code sections shouldn't be inside a ```text block.

r? @steveklabnik

[steveklabnik]

This is on purpose, actually. See the line right before: it's trying to show the literal syntax.

[ollie27]

But if you put

    ```text
    let x = 5;
    # let y = 6;
    # println!("{}", x + y);
    ```

It will result in the lines beginning with # being included which is what I thought this example was tying to avoid.

I guess if "our source code" is supposed to mean the source code of documentation.md then I think the text` lines inside this block need changing to rust`.

[steveklabnik]

It will result in the lines beginning with # being included which is what I thought this example was tying to avoid.

This example is trying to show you how to use the #s. So in this part of it, they need to be shown.

[steveklabnik]

That said you are right that

I think the text lines inside this block need changing torust.

They should be. Would you mind updating this PR to change that?

[ollie27]

Updated.

[steveklabnik]

@bors: r+ rollup

Thanks for sticking with me :)

[bors]

📌 Commit cff81d7 has been approved by steveklabnik