Use grid classes or mixins on .dl-horizontal, update docs to include it, removes auto truncate and makes .text-overflow mixin into a .text-truncate class and mixin combo for better granularity

scss/mixins/_text-truncate.scss

@@ -0,0 +1,8 @@
+// Text truncate
+// Requires inline-block or block for proper styling
+
+@mixin text-truncate() {
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}