This PR adds an installer script for local dev only.

It supports the following arguments:

Global command syntax:
        installer COMMAND [OPTIONS]

Accepted commands:
        help|h                                  Prints this help
        install|i                               Installs the dashboard
        uninstall|u                             Uninstalls the dashboard
        build|b                                 Builds the manifests and docker image and outputs manfiests in the console

Accepted options:
        [--debug]                               Prints additional messages in the console
        [--csrf-secure-cookie]                  Enable secure CSRF cookie
        [--openshift]                           Will build manifests for openshift
        [--read-only]                           Will build manifests for a readonly deployment
        [--namespace <namespace>]               Will override install namespace
        [--pipelines-namespace <namespace>]     Override the namespace where Tekton Pipelines is installed (defaults to tekton-pipelines)
        [--triggers-namespace <namespace>]      Override the namespace where Tekton Triggers is installed (defaults to tekton-pipelines)
        [--ingress-url <url>]                   Will create an additional ingress with the specified url
        [--ingress-secret <secret>]             Will add ssl support to the ingress