feat(tscn-to-bsn): add global help fallback support

Add a fallback module providing a help command that displays usage
information for the tool.

1 files changed, 13 insertions, 0 deletions

diff --git a/tools/tscn-to-bsn/src/fallback.rs b/tools/tscn-to-bsn/src/fallback.rs
new file mode 100644
index 0000000..99bdd13
--- /dev/null
+++ b/tools/tscn-to-bsn/src/fallback.rs
@@ -0,0 +1,13 @@
+use mingling::macros::{help, renderer};
+
+use crate::EntryFallback;
+
+#[help]
+pub fn help_global(_: EntryFallback) -> String {
+    include_str!("helps/help.txt").to_string()
+}
+
+#[renderer]
+pub fn render_global_hint(_: EntryFallback) -> String {
+    "Error: unknown command, please use `tscn2bsn /H` for help".into()
+}