Add help/usage message about savant

[spilth]

Hey @drmaas. For some reason I wasn't "watching" my own repo! I was just about to add this issue myself so thank you for already doing that :-)

[spilth]

This is now available in the latest version. General help:

$ savant -h
Usage: savant [options] [command] [command options]
  Options:
    --help, -h

  Commands:
    init      Initializes a new Java 8 Maven project
      Usage: init [options]
        Options:
          --artifactId, --artifact, -a
            Artifact ID
            Default: exampleArtifact
          --groupId, --group, -g
            Group ID
            Default: com.example
          --help, -h

          --minimal, -m
            Use Minimal Java 8 Archetype
            Default: false

    search      Searches Maven Central for dependencies
      Usage: search [options] Search term
        Options:
          --format, -f
            Dependency output format
            Default: maven
          --help, -h


    dash      Adds Maven project dependencies to Dash
      Usage: dash [options]
        Options:
          --pom, -p, --file, -f
            Source POM File
            Default: pom.xml
          --help, -h

And for each command:

$ savant init -h
Initializes a new Java 8 Maven project
Usage: init [options]
  Options:
    --artifactId, --artifact, -a
      Artifact ID
      Default: exampleArtifact
    --groupId, --group, -g
      Group ID
      Default: com.example
    --help, -h

    --minimal, -m
      Use Minimal Java 8 Archetype
      Default: false