docs(design): add larger source example

docs/design/graphics.typ

@@ -66,6 +66,7 @@
 #let stages-overview = canvas({
 	nodes(
 		[Source],
+    [AST],
 		[Graph IR],
 		[Runtime],
 	)

docs/design/iowo-design.typ

@@ -25,9 +25,14 @@
   clusters.insert(1, "\u{FEFF}")
   clusters.join()
 }
-// TODO: could make this just look over headings in section "Execution stages" tbh
+// even though it looks like this could be automated with a `query`,
+// this'd require wrapping the whole document in a show rule
+// at which point `query` doesn't find anything anymore
 #let terms = (
   "source",
+  "ast",
+  "abstract syntax tree",
+  "Abstract Syntax Tree",
   "graph IR",
   "runtime",
 
@@ -86,7 +91,15 @@
 
 #graphics.stages-overview
 
-== Source
+== Source <source>
+
+```iowo
+open base.png    >|
+open stencil.png >|
+mask
+|> (invert | show)
+|> show
+```
 
 Functional and pipeline-based.
 However, in contrast to classic shell commands,
@@ -180,6 +193,10 @@ Done with any of `--` or `//`.
 - Outputs of streamers are spliced into the contained list.
   - In effect, they are automatically flattened.
 
+== Abstract Syntax Tree
+
+Essentially just the source lexed and parsed.
+
 == Graph IR
 
 === Optimizer

docs/template.typ

@@ -38,7 +38,8 @@
   )
   show raw.where(block: false): box.with(
     fill: luma(95%),
-    outset: 0.25em,
+    outset: (y: 0.25em),
+    inset: (x: 0.15em),
     radius: 0.25em,
   )