`crate.select()` support (#1977)

Updates `crate.annotation()` to support `crate.select()`.

Also includes a bunch of hopefully desirable cleanups, like removing the
`serialize_starlark()` workaround that was no longer necessary.
diff --git a/docs/update_docs.sh b/docs/update_docs.sh
index 94890eb..edadbfa 100755
--- a/docs/update_docs.sh
+++ b/docs/update_docs.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 set -euo pipefail