They are distracting, and it is better to just have the links greyed out
like all the other pages that are not yet written.

Ion

Update preparing_the_build.md

The `bootstrap` script works as well on MacOS X

Add `override` statement

Add an additional description of how to install the nightly version of Rust, using `rustup`.

`multirust` is now deprecated - now use `rustup`

Added info on how to join chat.

Fix missing word

As reported in https://github.com/redox-os/redox/issues/629

Typo =)

Update shell.md

Many tweaks to the Redox Book

The changes include:
- Editing for flow and understandability.
- Unifying how links are included in the source files.
- Adding an `About this Book` page to the introduction.
- Adding a few examples or new pieces of information I felt were
  lacking when I read the book.
- Unifying 'user space' and 'kernel space' spelling.
- Added myself to the authors list in `overview/welcome.md`.

update preparing_the_build.md & compiling_redox.md

Fix minor spelling and grammatical issues

Minor edits to first 2 chapters

Update what_is_redox.md