Also bundle css with bun so it busts caches

And updates the `build.rs` script so that it also builds a manifest.txt
for css files.

frontend/css/styles.css

@@ -0,0 +1,79 @@
+/* Global */
+
+html {
+  font-size: 18px;
+  line-height: 1.6em;
+  font-family: Helvetica, Arial, sans-serif;
+}
+
+/* Header */
+
+header.header nav {
+  display: flex;
+  flex-direction: row;
+  align-items: baseline;
+}
+
+header.header nav h1 {
+  margin: 0;
+}
+
+header.header nav a {
+  text-decoration: none;
+}
+
+header.header nav ul {
+  display: flex;
+  flex-direction: row;
+  list-style: none;
+  margin: 0;
+  padding: 0;
+}
+
+header.header nav ul li {
+  margin-left: 16px;
+}
+
+/* Home */
+
+ul.entries {
+  list-style: none;
+  margin: 24px 8px;
+  padding: 0;
+}
+
+ul.entries li {
+  margin-bottom: 8px;
+}
+
+ul.entries li em.domain {
+  margin-left: 8px;
+  color: rgba(0, 0, 0, 0.75);
+}
+
+/* Log */
+
+pre#log {
+  font-size: 12px;
+  line-height: 1.2em;
+}
+
+/* Entry */
+
+article {
+  max-width: 35em;
+  margin: 0 auto;
+  font-size: 18px;
+}
+
+article span.published {
+  font-size: 16px;
+  line-height: 1.2em;
+}
+
+article img {
+  max-width: 100%;
+  max-height: 100%;
+  width: auto;
+  height: auto;
+}