feat(typst): add more folds

for the following language constructs:

- 'for' blocks
- 'if/else' expressions
- raw markup blocks (```)
- `content`

queries/typst/folds.scm

@@ -4,4 +4,8 @@
   (show)
   (call)
   (section)
+  (for)
+  (branch)
+  (content)
+  (raw_blck)
 ] @fold