Changes

Remove verbose output by default

Make use of the --silent flag to remove verbose npm output, e.g.

npm ERR! code 4
npm ERR! path /pyright-python
npm ERR! command failed
npm ERR! command sh -c pyright --foo

npm ERR! A complete log of this run can be found in:
npm ERR!     /Users/robert/.npm/_logs/2021-09-26T11_00_20_456Z-debug.log

This output can be re-enabled by setting PYRIGHT_PYTHON_VERBOSE to a truthy value.

Bug Fixes

• Fix bug with npx passing the argument separator -- to pyright