refactor(odyssey)!: renames "title" variables to "heading"

packages/odyssey/src/scss/abstracts/_tokens.scss

@@ -20,17 +20,17 @@ $mono-font-family: "Inconsolata", "SFMono-Regular", "Consolas",
 $base-font-size: 16px;
 $scale-ratio: 1.1487;
 $base-line-height: 1.5;
-$title-line-height: 1.3;
+$heading-line-height: 1.3;
 $max-line-length: 32em;
 $type-margin: 1.5em;
 
 // Establish Type Scale
-$size-title-1: ms(5);
-$size-title-2: ms(4);
-$size-title-3: ms(3);
-$size-title-4: ms(2);
-$size-title-5: ms(1);
-$size-title-6: ms(0);
+$size-heading-1: ms(5);
+$size-heading-2: ms(4);
+$size-heading-3: ms(3);
+$size-heading-4: ms(2);
+$size-heading-5: ms(1);
+$size-heading-6: ms(0);
 
 $size-body-lede: ms(1);
 $size-body-base: ms(0);