Add "API Listing" sections to doc/std
diff --git a/doc/std/compression-decoders.md b/doc/std/compression-decoders.md
index 19a0d45..e3be6d6 100644
--- a/doc/std/compression-decoders.md
+++ b/doc/std/compression-decoders.md
@@ -20,6 +20,15 @@
 TODO: standardize the various dictionary APIs, after Wuffs v0.2 is released.
 
 
+## API Listing
+
+In Wuffs syntax, the `base.io_transformer` methods are:
+
+- `set_quirk_enabled!(quirk: u32, enabled: bool)`
+- `transform_io?(dst: io_writer, src: io_reader, workbuf: slice u8)`
+- `workbuf_len() range_ii_u64`
+
+
 ## Implementations
 
 - [std/deflate](/std/deflate)
diff --git a/doc/std/hashers.md b/doc/std/hashers.md
index 849bbd7..f71b2a3 100644
--- a/doc/std/hashers.md
+++ b/doc/std/hashers.md
@@ -19,6 +19,14 @@
 resist timing attacks.
 
 
+## API Listing
+
+In Wuffs syntax, the `base.hasher_u32` methods are:
+
+- `set_quirk_enabled!(quirk: u32, enabled: bool)`
+- `update_u32!(x: slice u8) u32`
+
+
 ## Implementations
 
 - [std/adler32](/std/adler32)
diff --git a/doc/std/image-decoders.md b/doc/std/image-decoders.md
index c3c087a..df6cc40 100644
--- a/doc/std/image-decoders.md
+++ b/doc/std/image-decoders.md
@@ -111,6 +111,24 @@
 caller can go back to the `decode_image_config` method.
 
 
+## API Listing
+
+In Wuffs syntax, the `base.image_decoder` methods are:
+
+- `decode_frame?(dst: ptr pixel_buffer, src: io_reader, blend: pixel_blend, workbuf: slice u8, opts: nptr decode_frame_options)`
+- `decode_frame_config?(dst: nptr frame_config, src: io_reader)`
+- `decode_image_config?(dst: nptr image_config, src: io_reader)`
+- `frame_dirty_rect() rect_ie_u32`
+- `num_animation_loops() u32`
+- `num_decoded_frame_configs() u64`
+- `num_decoded_frames() u64`
+- `restart_frame!(index: u64, io_position: u64) status`
+- `set_quirk_enabled!(quirk: u32, enabled: bool)`
+- `set_report_metadata!(fourcc: u32, report: bool)`
+- `tell_me_more?(dst: io_writer, minfo: nptr more_information, src: io_reader)`
+- `workbuf_len() range_ii_u64`
+
+
 ## Implementations
 
 - [std/bmp](/std/bmp)