release: 0.6.0: Delivery detail page, DNS badge, machine metrics, wide layout

A page per delivery (`/deliveries/{id}`), reached from the *Details* link on
Added:
  - A page per delivery (`/deliveries/{id}`), reached from the *Details* link on
  - A **DNS** badge in the domain list, one per row, carrying the same
  - Machine metrics on the status page: a **Machine** card reporting the
  - An index of the current page's own sections in the navigation column, for the
Changed:
  - Every panel page is laid out in one column of the same width, so moving
  - The mark's small-size variant — the tab icon and the `SP` initials it
  - The stamp's `SELF-HOSTED SMTP RELAY` line is set at 11.5/0.15 instead of
  - The delivery log lists what identifies a message and nothing else: time,
  - Subjects are decoded for display as well as on the way in, so the rows the
  … (4 more in CHANGELOG)

Full detail: CHANGELOG.md (0.6.0).

internal/web/templates/dashboard.html

@@ -22,12 +22,13 @@
   {{if .Domains}}
   <table>
     <thead>
-      <tr><th>Domain</th><th>Selector</th><th>Apps</th><th></th></tr>
+      <tr><th>Domain</th><th>DNS</th><th>Selector</th><th>Apps</th><th></th></tr>
     </thead>
     <tbody>
       {{range .Domains}}
       <tr>
         <td><a href="/domains/{{.ID}}">{{.Name}}</a></td>
+        <td><a class="st st-{{.DNS}}" href="/domains/{{.ID}}#dns-status">{{.DNS}}</a></td>
         <td class="muted">{{.DKIMSelector}}</td>
         <td>{{.AppCount}}</td>
         <td class="actions"><a class="danger" href="/domains/{{.ID}}/delete">Delete</a></td>
@@ -35,6 +36,9 @@
       {{end}}
     </tbody>
   </table>
+  <p class="muted">The <em>DNS</em> badge is the worst of the domain's DKIM, SPF
+  and DMARC checks. Results are cached for a few minutes; open a domain for the
+  details and a <em>Re-check</em> button.</p>
   {{else}}
   <p class="muted">No domains yet. Add one above to get started.</p>
   {{end}}