Move bergamot and writing CSS into theme

Signed-off-by: Danila Fedorin <danila.fedorin@gmail.com>

assets/scss/writing.scss

@@ -0,0 +1,47 @@
+@import "variables.scss";
+
+body {
+  background-color: #1c1e26;
+  --text-color: white;
+  font-family: $font-code;
+}
+
+h1, h2, h3, h4, h5, h6 {
+  text-align: left;
+  font-family: $font-code;
+}
+
+h1::after {
+  content: "(writing)";
+  font-size: 1rem;
+  margin-left: 0.5em;
+  position: relative;
+  bottom: -0.5em;
+  color: $primary-color;
+}
+
+nav .container {
+  justify-content: flex-start;
+
+  a {
+    padding-left: 0;
+    margin-right: 1em;
+  }
+}
+
+.header-divider {
+  visibility: hidden;
+}
+
+hr {
+  height: auto;
+  border: none;
+
+  &::after {
+    content: "* * *";
+    color: $primary-color;
+    font-size: 2rem;
+    display: block;
+    text-align: center;
+  }
+}