Imgui (#20)

* vendor/cimgui

* Add a "dev mode" window which for now is just imgui demo

src/input/Binding.zig

@@ -140,6 +140,9 @@ pub const Action = union(enum) {
     /// Copy and paste.
     copy_to_clipboard: Void,
     paste_from_clipboard: Void,
+
+    /// Dev mode
+    toggle_dev_mode: Void,
 };
 
 /// Trigger is the associated key state that can trigger an action.

src/input/key.zig

@@ -49,6 +49,9 @@ pub const Key = enum {
     y,
     z,
 
+    // other
+    grave_accent, // `
+
     // control
     up,
     down,