website: long checksums and URLs no longer scroll a phone sideways

Measured at 390px on the LIVE pages, so this is pre-existing and not something the
shell introduced:
  /letoltes    scrollWidth 609 - the 64-character SHA-256 inside <code>
  /adatkezeles scrollWidth 478 - a long facebook.com legal URL used as link text
and the same on their English twins.

overflow-wrap: anywhere changes only where the line breaks; selecting and copying
still yields the whole unbroken string, which matters for a checksum. The legal
pages' words are untouched - this is CSS.

Small enough to fix in the session rather than file.

website/preview/m3/en/testing.html

@@ -38,8 +38,8 @@
     }
     </script>
     <!-- shared assets: bump ?v= together on any site.css/icons.svg change -->
-    <link rel="stylesheet" href="/assets/site.css?v=19">
-    <link rel="stylesheet" href="/assets/shell.css?v=19">
+    <link rel="stylesheet" href="/assets/site.css?v=20">
+    <link rel="stylesheet" href="/assets/shell.css?v=20">
     <link rel="icon" type="image/png" href="/assets/logo_favicon_2.svg">
     <script defer src="https://stats.felhom.eu/script.js" data-website-id="d419db57-5e1c-48df-bdb3-c29f25fb1661"></script>
 </head>