docs: add language spec, domain glossary, and fixture update

fixtures/basic.md

@@ -10,18 +10,7 @@ source: https://example.com/pancakes
 A simple weekend breakfast that comes together in minutes.
 Pairs well with [[maple syrup]] or fresh fruit from the [[farmers market]].
 
-## Ingredients
-
-- @flour{200 g}
-- @milk{300 ml}
-- @eggs{2}
-- @unsalted butter{30 g}
-- @baking powder{1 tsp}
-- @salt{0.5 tsp}
-
-## Method
-
-### Batter
+## Batter
 
 Sift @flour{200 g} and @baking powder{1 tsp} into a $mixing bowl{} along with @salt{0.5 tsp}.
 Make a well in the centre and crack in @eggs{2}.