✨ feat(cli): add short description to tab completion in bash

[vitorfloriano]

This PR enhances the tab completion in bash with a short description for all available subcommands and flags, similar to kubectl and docker tab completion.

Current completion in bash:

$ kubebuilder
alpha       completion  create      edit        help        init        version

$ kubebuilder init --
--domain                 --license                --owner=                 --project-name           --project-version=       --skip-go-version-check
--domain=                --license=               --plugins                --project-name=          --repo
--fetch-deps             --owner                  --plugins=               --project-version        --repo=

New completion in bash:

$ kubebuilder
alpha       (Alpha-stage subcommands)                   help        (Help about any command)
completion  (Load completions for the specified shell)  init        (Initialize a new project)
create      (Scaffold a Kubernetes API or webhook)      version     (Print the kubebuilder version)
edit        (Update the project configuration)

$ kubebuilder init --
--domain                 (domain for groups)
--fetch-deps             (ensure dependencies are downloaded)
--help                   (help for init)
--license                (license to use to boilerplate, may be one of 'apache2', 'none')
--owner                  (owner to add to the copyright)
--plugins                (plugin keys to be used for this subcommand execution)
--project-name           (name of this project)
--project-version        (project version)
--repo                   (name to use for go module (e.g., github.com/user/repo), defaults to the go package of the current working directory.)
--skip-go-version-check  (if specified, skip checking the Go version)

This greatly improves the UX and allows us to add examples to the short descriptions in follow-ups.

[vitorfloriano]

/retest

[camilamacedo86]

/lgtm

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: camilamacedo86, vitorfloriano

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