:title
Set a named child

:sig
function set(dest : dval, key : string, value : as dval) dval

:params
dest : target value
key : child key
value : value to store

:returns
The changed target value.

:content
`set(dest, key, value)` stores `value` at `key`. It changes and returns `dest`.

:example capy render
var user := dval({})
user = set(user, "name", "Ada")
print(user.name, "\n")

:see-group
dval-access
