adds Proof-of-work book to page/learn

Author: benlazzero

src/intl/en/page-learn.json

@@ -100,6 +100,7 @@
   "online-communities-card-description": "Online communities provide a great opportunity to ask more specific questions or get involved.",
   "online-communities-card-button": "Explore communities",
   "books-about-ethereum": "Books about Ethereum and Cryptocurrencies",
+  "proof-of-stake-description": "September 13, 2022 - Vitalik Buterin, Nathan Schneider",
   "cryptopians-description": "February 22, 2022 - Laura Shin",
   "out-of-the-ether-description": "September 29, 2020 - Matthew Leising",
   "the-infinite-machine-description": "July 14, 2020 - Camila Russo",

src/pages/learn/index.tsx

@@ -799,6 +799,14 @@ const LearnPage = ({ data }: PageProps<Queries.LearnPageQuery, Context>) => {
                 <Translation id="books-about-ethereum" />
               </h3>
               <ul>
+                <li>
+                  <Link to="https://www.goodreads.com/en/book/show/59892281-proof-of-stake">
+                    Proof of Stake
+                  </Link>{" "}
+                  <i>
+                    <Translation id="proof-of-stake-description" />
+                  </i>
+                </li>
                 <li>
                   <Link to="https://www.goodreads.com/book/show/57356067-the-cryptopians">
                     The Cryptopians