docs: Tables in docs now easier to read, as aligned (#1425)

The Quick Reference table, especially, was quite hard to glance over
quickly due to the inconsistent vertical alignment.

Author: claremacrae

docs/_sass/custom/custom.scss

@@ -6,3 +6,7 @@ blockquote {
     padding-left: 15px;
     border-left: 3px solid #ccc;
 }
+
+td {
+    vertical-align: top;
+}