`kctrl` Enhance Kctrl package authoring documentation

- [x] Document pre-reqs
- [x] Identify k8s config - Mention that kctrl accepts ytt template files or helm template file
- [x] Update current documentation for making a release using kctrl package commands
- [x] add `values.yml` file usage.
- [x] Mention that Package-build, package-resources.yml and pkg-repo-build.yml needs to be checked-in into the git repo.
- [x] Add notes for kbld FAQ - Create container binary/image from source code while releasing a package.
- [ ] Document how to iterate (or update the inputs in init flow) - explain that init can be re-run. In case of failure on incorrect entries users can re-run init. Call out that we will over write if release is done again with same version. (explain repo output flag)- highlight
- [ ] Documentation for making a new release (new version) using from an existing release - it is in FAQs, move it to tutorials
- [ ] Standardising the folder structure, write scripts for operation
- [x] Document which app template section gets picked for which kctrl command? e.g. explain PackageBuild
- [x] Clarify how stdin input is piped in app template - Add documentation for kapp-controller to inform that `kbld` can consume `ytt` output using

- [ ] Add video series for kctrl-101
- [ ] Add Notes using Markdown
- [ ] Update doc for the new release of application from github action.