refactor!: deprecate .prose class and lint

src/partials/title.scss

@@ -0,0 +1,89 @@
+h1 {
+  margin-top: 0;
+  margin-bottom: .875rem;
+  color: var(--xm-c-deeper);
+  font-weight: 800;
+  font-size: 2.25rem;
+  line-height: 1.15;
+}
+h2 {
+  margin-top: 2rem;
+  margin-bottom: 1rem;
+  color: var(--xm-c-deep);
+  font-weight: 700;
+  font-size: 1.5rem;
+  line-height: 1.35;
+  code {
+    font-size: .875rem;
+  }
+  + * {
+    margin-top: 0;
+  }
+}
+h3 {
+  margin-top: 1.6rem;
+  margin-bottom: .6rem;
+  color: inherit;
+  font-weight: 600;
+  font-size: 1.25rem;
+  line-height: 1.6;
+  opacity: .7;
+  code {
+    font-size: .9rem;
+  }
+  + * {
+    margin-top: 0;
+  }
+}
+h4 {
+  margin-top: 1.5rem;
+  margin-bottom: .5rem;
+  color: inherit;
+  font-weight: 600;
+  line-height: 1.5;
+  + * {
+    margin-top: 0;
+  }
+}
+h5,
+h6 {
+  margin-top: 20px;
+  margin-bottom: 10px;
+  font-weight: 500;
+  letter-spacing: 2px;
+  text-transform: uppercase;
+  opacity: .5;
+}
+hr {
+  width: 50px;
+  margin-top: 2rem;
+  margin-bottom: 2rem;
+  border-color: var(--xm-c-hr-border);
+  + * {
+    margin-top: 0;
+  }
+}
+.header-anchor {
+  float: left;
+  margin-top: .125rem;
+  margin-left: -1.25rem;
+  padding-right: .5rem;
+  border: 0 !important;
+  font-size: .875rem;
+  text-decoration: none;
+  opacity: 0;
+  &:hover,
+  &:focus {
+    text-decoration: none;
+  }
+}
+@for $i from 1 through 6 {
+  h#{$i} {
+    &:hover,
+    &:focus {
+      .header-anchor {
+        opacity: .35 + $i * .025;
+      }
+    }
+  }
+}