Add "Fork on GitHub" to footer

A prior commit removed the "Fork me on GitHub" ribbon.
This adds the link to the footer.

Author: ridiculousfish

app/components/footer.hbs

@@ -1,7 +1,5 @@
 <footer local-class="footer">
   <div local-class='after-main-links'>
-    <a href='https://doc.rust-lang.org/cargo/getting-started/installation.html'>Install</a>
-    <span local-class="sep">|</span>
     <a href='https://doc.rust-lang.org/cargo/'>Getting started</a>
     <span local-class="sep">|</span>
     <a href='https://doc.rust-lang.org/cargo/guide/'>Guide</a>
@@ -10,6 +8,8 @@
     <span local-class="sep">|</span>
     <a href='https://www.rust-lang.org/policies/security'>Report a security issue</a>
     <span local-class="sep">|</span>
+    <a href='https://github.com/rust-lang/crates.io'>Fork on GitHub</a>
+    <span local-class="sep">|</span>
     <a href='https://www.rust-lang.org/policies/privacy'>Privacy notice</a>
     <span local-class="sep">|</span>
     <LinkTo @route="policies">Policies</LinkTo>

app/components/footer.module.css

@@ -6,7 +6,7 @@
 }
 
 .sep {
-    margin: 0 10px;
+    margin: 0 5px;
     color: var(--separator-color);
 }