CLI command to run log pretty over stdin

[jasonkuhrt]

What

• Allow the logger prettier module to be run over NDJSON coming from stdin
• A new cli command e.g. $ santa logger

• Example:

  $ kubectl logs -f my-pod | santa logger

  kubectl logs ref

  $ tail -f my-log-file | santa logger

Why

• Makes it possible to enjoy pretty log mode on remote logs
• Similar motivation to why pino has this feature

[jasonkuhrt]

@Weakky pointed out that, at least for as long as we do not have #268, we can point users to filtering patterns like:

 $ tail -f my-log-file | grep '...' | santa logger

If they prefer regex they could use pcregrep.

 $ tail -f my-log-file | pcregrep '[bar]+|foo' | santa logger

[jasonkuhrt]

Refinement:

• We recognize that main part of work here is setting up a new sub-command and getting process.stdin to be sent to the existing Logger.prettifier.render function.