consistently use dash as word separator in URLs

static/donate.html

@@ -19,7 +19,7 @@
         <meta property="og:url" content="https://grapheneos.org/donate"/>
         <meta property="og:site_name" content="GrapheneOS"/>
         <link rel="icon" type="image/vnd.microsoft.icon" href="/favicon.ico"/>
-        <link rel="mask-icon" href="/safari_pinned_tab_icon.svg" color="#000000"/>
+        <link rel="mask-icon" href="/safari-pinned-tab-icon.svg" color="#000000"/>
         <link rel="stylesheet" href="/grapheneos.css?13"/>
         <link rel="manifest" href="/manifest.webmanifest"/>
         <link rel="canonical" href="https://grapheneos.org/donate"/>
@@ -48,7 +48,7 @@
             <p>You can send Bitcoin donations to the following address to support this project:</p>
             <div id="bitcoin_address">
                 <a href="bitcoin:3QpKs45BLXirWAgYtV1sTCbAkfUe7HByR5">
-                    <img src="/bitcoin_address.png" alt="Bitcoin address QR code" width="160" height="160"/>
+                    <img src="/bitcoin-address.png" alt="Bitcoin address QR code" width="160" height="160"/>
                     <p>3QpKs45BLXirWAgYtV1sTCbAkfUe7HByR5</p>
                 </a>
             </div>