[bug] Unable to read stdin

[gczuczy]

We're validating embedded content in various YAML files, basically we have to grab what's inside a doc, and send the output to the validator's way. The most trivial way is to pipe it, however yajsv doesn't know the concept of stdin:

$ yq .some.path doc.yaml | yajsv -s schema.json -
-: no such file or directory

Could this be fixed please? This is a valid usecase.