Remove Polkadot tab from UI (OpenZeppelin#682)

Author: ericglau

packages/ui/public/cairo.html

@@ -73,7 +73,6 @@
           <option value="alpha" />
         </select>
       </div>
-      <a class="switch switch-polkadot" href="/polkadot"><img src="/icons/polkadot.svg" alt="polkadot">Polkadot</a>
       <a class="switch switch-stellar" href="/stellar"><img src="/icons/stellar.svg" alt="stellar">Stellar</a>
       <a class="switch switch-stylus" href="/stylus"><img src="/icons/stylus.svg" alt="stylus">Stylus</a>
     </div>

packages/ui/public/index.html

@@ -97,7 +97,6 @@
     <div class="nav nav-switches flex flex-row">
       <a class="switch switch-solidity active" href="/"><img src="/icons/solidity.svg" alt="solidity">Solidity</a>
       <a class="switch switch-cairo" href="/cairo"><img src="/icons/cairo.svg" alt="cairo">Cairo</a>
-      <a class="switch switch-polkadot" href="/polkadot"><img src="/icons/polkadot.svg" alt="polkadot">Polkadot</a>
       <a class="switch switch-stellar" href="/stellar"><img src="/icons/stellar.svg" alt="stellar">Stellar</a>
       <a class="switch switch-stylus" href="/stylus"><img src="/icons/stylus.svg" alt="stylus">Stylus</a>
     </div>

packages/ui/public/polkadot.html

@@ -65,7 +65,6 @@
     <div class="nav">
       <a class="switch switch-solidity" href="/"><img src="/icons/solidity.svg" alt="solidity">Solidity</a>
       <a class="switch switch-cairo" href="/cairo"><img src="/icons/cairo.svg" alt="cairo">Cairo</a>
-      <a class="switch switch-polkadot" href="/polkadot"><img src="/icons/polkadot.svg" alt="polkadot">Polkadot</a>
       <a class="switch switch-stellar active" href="#"><img src="/icons/stellar.svg" alt="stellar">Stellar</a>
       <a class="switch switch-stylus" href="/stylus"><img src="/icons/stylus.svg" alt="stylus">Stylus</a>
     </div>

packages/ui/public/stellar.html

@@ -65,7 +65,6 @@
     <div class="nav">
       <a class="switch switch-solidity" href="/"><img src="/icons/solidity.svg" alt="solidity">Solidity</a>
       <a class="switch switch-cairo" href="/cairo"><img src="/icons/cairo.svg" alt="cairo">Cairo</a>
-      <a class="switch switch-polkadot" href="/polkadot"><img src="/icons/polkadot.svg" alt="polkadot">Polkadot</a>
       <a class="switch switch-stellar" href="/stellar"><img src="/icons/stellar.svg" alt="stellar">Stellar</a>
       <a class="switch switch-stylus active" href="#"><img src="/icons/stylus_active.svg" alt="stylus">Stylus</a>
     </div>