feat: markdown in email body for mailing and transactional

assets/styles/components/mail-body.css

@@ -0,0 +1,41 @@
+/*
+ * Mirrors the rules the mail layout carries in assets/mjml/layout.mjml, so both admin
+ * previews show what the rendered mail will look like. Kept out of Tailwind's typography
+ * plugin on purpose: prose brings its own type scale, and the point here is to match the
+ * mail rather than to look good on its own.
+ */
+.mail-body > p {
+    @apply pb-4;
+}
+
+.mail-body h2 {
+    @apply text-xl pb-2;
+}
+
+.mail-body h3 {
+    @apply text-lg font-bold pb-1;
+}
+
+.mail-body strong {
+    @apply font-bold;
+}
+
+.mail-body em {
+    @apply italic;
+}
+
+.mail-body ul {
+    @apply list-disc ml-6 pb-4;
+}
+
+.mail-body ol {
+    @apply list-decimal ml-6 pb-4;
+}
+
+.mail-body li {
+    @apply pb-1;
+}
+
+.mail-body a {
+    @apply underline;
+}