chore(weave): remove todo block in docs on object (#1619)

docs/docs/guides/tracking/objects.md

@@ -48,10 +48,3 @@ Refs can be constructed with a few different styles
 - `weave.ref(<name>)`: requires `weave.init(<project>)` to have been called. Refers to the ":latest" version
 - `weave.ref(<name>:<version>)`: requires `weave.init(<project>)` to have been called.
 - `weave.ref(<fully_qualified_ref_uri>)`: can be constructed without calling weave.init
-
-## TODO
-
-- iterating through other versions of an object
-- navigating to consuming and producing calls via the API
-- declaring how to serializes other types of objects
-- @weave.type()