lint: fix issues in examples (#49)

script/generate

@@ -8,7 +8,7 @@ post=$(go list ./... | grep -E  'avo/(examples|tests)')
 go install ./internal/cmd/avogen
 
 # Attempt to delete generated files, to prove we can recreate them.
-grep -REl 'Code generated.*DO NOT EDIT\.$' . | grep -v '.md$' | xargs rm -v
+grep -RE '^// Code generated.*DO NOT EDIT\.$' . | grep -v download | cut -d: -f1 | grep -v '.md$' | xargs rm -v
 
 # Generate once.
 go generate -v -x ${core}