Redirecting Error in Book

[DebugSteven]

🐛 Bug description

When you click on the documentation link from the wasm pack URL, the documentation URL has the path /wasm-pack/book/. This breaks the links listed in the body of the page for Rust & NPM which are expecting a path of /wasm-pack/book/prerequisites/.

🤔 Expected Behavior

The links for Rust & NPM should be redirected to regardless of how you navigate to the prerequisites section in the wasm pack book.

👟 Steps to reproduce

Start from the repo
Click on the tutorial URL linked in the description
Click on the documentation nav-bar element
Notice the URL shows https://rustwasm.github.io/wasm-pack/book/
In the page, click the link for Rust
You are redirected to https://rustwasm.github.io/wasm-pack/book/rust.html
OR
In the page, click the link for NPM
You are redirected to https://rustwasm.github.io/wasm-pack/book/npm.html
Both result in a 404 page not found

Environment

This was on firefox 64.0.2. I think this issue is browser agnostic.

Possible Fix

I believe the code that sets the current path for the wasm pack book is here:

wasm-pack/docs/index.html

Line 28 in c8410f2

<a href="/wasm-pack/book">Documentation</a>

This could be possibly be changed to
<a href="/wasm-pack/book/prerequisites/">Documentation</a>
or
<a href="/wasm-pack/book/prerequisites/index.html">Documentation</a>

I tested those solutions & both seemed to work.

[drager]

Thank you for this report @DebugSteven! I pushed a fix in #514 that I hope will fix this as well as some other broken links.