added 2022 button for paper filter

public/index.html

@@ -193,6 +193,7 @@
       <button class="btn" style="background-color: lightgray;" id="filter2019" onclick="filter(2019)">2019</button>
       <button class="btn" style="background-color: lightgray;" id="filter2020" onclick="filter(2020)">2020</button>
       <button class="btn" style="background-color: lightgray;" id="filter2021" onclick="filter(2021)">2021</button>
+	  <button class="btn" style="background-color: lightgray;" id="filter2022" onclick="filter(2022)">2022</button>
     </div>
     <div class="container" id="cont_paper">
       <!-- <div class="card" style="max-width: 1080px;">