Update book links

Author: jamesmunns

templates/what/embedded/get-started.hbs

@@ -8,7 +8,7 @@
       <div class="four columns" id="discovery-book">
         <div class="domain-icon">
           <img src="/static/images/chip1.svg" alt="DIP-6 package"/>
-          <a href="https://japaric.github.io/discovery">
+          <a href="https://rust-embedded.github.io/discovery/">
             <h3>The Discovery Book</h3>
           </a>
         </div>
@@ -19,7 +19,7 @@
       <div class="four columns" id="embedded-rust-book">
         <div class="domain-icon">
           <img src="/static/images/chip2.svg" alt="TFQP-16 package"/>
-          <a href="https://book.rust-embedded.org/">
+          <a href="https://rust-embedded.github.io/book/">
             <h3>The Embedded Rust Book</h3>
           </a>
         </div>
@@ -31,7 +31,7 @@
       <div class="four columns" id="embedonomicon">
         <div class="domain-icon">
           <img src="/static/images/chip3.svg" alt="BGA package" />
-          <a href="https://embedonomicon.rust-embedded.org/">
+          <a href="https://rust-embedded.github.io/embedonomicon/">
             <h3>The Embedonomicon</h3>
           </a>
         </div>

templates/what/embedded/pitch.hbs

@@ -24,7 +24,7 @@
         <p>
           Dynamic memory allocation is optional. Use a global allocator and dynamic data structures.
           Or leave out the heap altogether and statically allocate everything.
-          <a href="https://github.com/rust-lang-nursery/embedded-wg/issues/125">Learn more</a>
+          <a href="https://github.com/rust-embedded/book/issues/8">Learn more</a>
         </p>
       </div>
       <div class="four columns" id="safe-concurrency">
@@ -35,7 +35,7 @@
         <p>
           Rust makes it impossible to accidentally share state between threads.
           Use any concurrency approach you like, and you'll still get Rust's strong guarantees.
-          <a href="https://github.com/rust-lang-nursery/embedded-wg/issues/124">Learn more</a>
+          <a href="https://github.com/rust-embedded/book/issues/7">Learn more</a>
         </p>
       </div>
     </div>
@@ -48,7 +48,7 @@
         <p>
           Integrate Rust into your existing C codebase or leverage an existing SDK to write a Rust
           application.
-          <a href="https://github.com/rust-lang-nursery/embedded-wg/issues/48">Learn more</a>
+          <a href="https://github.com/rust-embedded/book/issues/1">Learn more</a>
         </p>
       </div>
       <div class="four columns" id="portability">
@@ -59,7 +59,7 @@
         <p>
           Write a library or driver once, and use it with a variety of systems, ranging
           from very small microcontrollers to powerful SBCs.
-          <a href="https://github.com/rust-lang-nursery/embedded-wg/issues/119">Learn more</a>
+          <a href="https://github.com/rust-embedded/book/issues/6">Learn more</a>
         </p>
       </div>
       <div class="four columns">