add read me

venv/lib/python3.12/site-packages/av/descriptor.pxd

@@ -0,0 +1,20 @@
+cimport libav as lib
+
+
+cdef class Descriptor:
+
+    # These are present as:
+    # - AVCodecContext.av_class (same as avcodec_get_class())
+    # - AVFormatContext.av_class (same as avformat_get_class())
+    # - AVFilterContext.av_class (same as avfilter_get_class())
+    # - AVCodec.priv_class
+    # - AVOutputFormat.priv_class
+    # - AVInputFormat.priv_class
+    # - AVFilter.priv_class
+
+    cdef const lib.AVClass *ptr
+
+    cdef object _options  # Option list cache.
+
+
+cdef Descriptor wrap_avclass(const lib.AVClass*)