misc mod and doc changes

src/commands/bitmap_command.rs

@@ -23,6 +23,10 @@ pub unsafe extern "C" fn sp_cmd_bitmap_new(
     })
 }
 
+/// Move the provided [Bitmap] into a new [BitmapCommand],
+/// leaving other fields as their default values.
+///
+/// Rust equivalent: [`<BitmapCommand as From<Bitmap>>::from`]
 #[no_mangle]
 pub unsafe extern "C" fn sp_cmd_bitmap_from_bitmap(
     bitmap: NonNull<Bitmap>,

src/commands/mod.rs

@@ -3,3 +3,9 @@ mod bitvec_command;
 mod brightness_grid_command;
 mod char_grid_command;
 mod cp437_grid_command;
+
+pub use bitmap_command::*;
+pub use bitvec_command::*;
+pub use brightness_grid_command::*;
+pub use char_grid_command::*;
+pub use cp437_grid_command::*;