Link to RSS feeds (#677)

* Link to RSS feeds

* Move RSS links to footer

Thanks to @XAMPPRocky, who came up with this layout!

* Use a flex row around social icons

* Increase top margin for RSS header

Author: camelid

templates/footer.hbs

@@ -21,10 +21,17 @@
       </div>
       <div class="four columns mt3 mt0-l">
         <h4>Social</h4>
-        <a href="https://twitter.com/rustlang" target="_blank" rel="noopener" alt="twitter link"><img src="/images/twitter.svg" alt="twitter logo" title="Twitter"/></a>
-        <a href="https://www.youtube.com/channel/UCaYhcUwRBNscFNUKTjgPFiA" target="_blank" rel="noopener" alt="youtube link"><img style="padding-top: 6px; padding-bottom:6px" src="/images/youtube.svg" alt="youtube logo" title="YouTube"/></a>
-        <a href="https://discord.gg/rust-lang" target="_blank" rel="noopener" alt="discord link"><img src="/images/discord.svg" alt="discord logo" title="Discord"/></a>
-        <a href="https://github.com/rust-lang" target="_blank" rel="noopener" alt="github link"><img src="/images/github.svg" alt="github logo" title="GitHub"/></a>
+        <div class="flex flex-row flex-wrap">
+          <a href="https://twitter.com/rustlang" target="_blank" rel="noopener" alt="twitter link"><img src="/images/twitter.svg" alt="twitter logo" title="Twitter"/></a>
+          <a href="https://www.youtube.com/channel/UCaYhcUwRBNscFNUKTjgPFiA" target="_blank" rel="noopener" alt="youtube link"><img style="padding-top: 6px; padding-bottom:6px" src="/images/youtube.svg" alt="youtube logo" title="YouTube"/></a>
+          <a href="https://discord.gg/rust-lang" target="_blank" rel="noopener" alt="discord link"><img src="/images/discord.svg" alt="discord logo" title="Discord"/></a>
+          <a href="https://github.com/rust-lang" target="_blank" rel="noopener" alt="github link"><img src="/images/github.svg" alt="github logo" title="GitHub"/></a>
+        </div>
+        <h4 class="mt4 mb3">RSS</h4>
+        <ul>
+          <li><a href="/feed.xml">Main Blog</a></li>
+          <li><a href="/inside-rust/feed.xml">"Inside Rust" Blog</a></li>
+        </ul>
       </div>
 
     </div>