chore: ignore *.raw scratch files

testdata/ktys.raw is a local capture, matching how *.txt and *.json are already
treated in this repo.

Author: kevinpinscoe

.gitignore

@@ -2,6 +2,7 @@ bin/
 dist/
 *.txt
 *.json
+*.raw
 __debug_bin*
 .vscode/
 *.code-workspace