Add tool to convert grammar to ebnf (#6995)

Author: dnwpark

edb/.gitignore

@@ -2,4 +2,7 @@
 *.html
 
 # Grammar spec file encoded as BitCode
-*.bc
+*.bc
+
+# Grammar spec file encoded as EBNF
+*.ebnf

edb/tools/edb.py

@@ -89,5 +89,6 @@ def load_ext(args: tuple[str, ...]):
 from . import ls_forbidden_functions  # noqa
 from . import redo_metaschema  # noqa
 from . import ls  # noqa
+from . import railroad_diagram  # noqa
 from .profiling import cli as prof_cli  # noqa
 from .experimental_interpreter import edb_entry # noqa