Create new project layout for refactor/rewrite

[ChrisJStone]

This issue is to introduce a new project layout as the starting point for the major refactor/rewrite outlined in the README. The goal is to establish a modern, maintainable structure to support upcoming improvements to gitflow-cjs.

Proposed Project Layout

gitflow-cjs/
+-- bin/
    +-- gitflow-cjs
+-- lib/
    +-- bootstrap.sh
    +-- platform.sh
    +-- fs.sh
    +-- process.sh
    +-- git.sh
    +-- ui.sh
    +-- config.sh
    +-- commands/
        +-- init.sh
        +-- feature.sh
        +-- release.sh
        +-- hotfix.sh
+-- share/
    +-- templates/
    +-- completions/
+-- test/
    +-- fixtures/
    +-- bats/
        +-- helpers/
            +-- common.bash
        +-- unit/
        +-- integration/
    +-- shellspec/
        +-- spec/
        +-- helper/
            +-- spec_helper.sh
        +-- support/
+-- scripts/
    +-- _common.sh
    +-- lint.sh
    +-- test-bats.sh
    +-- test-shellspec.sh
    +-- test.sh
    +-- qa.sh
    +-- install.sh
    +-- uninstall.sh
+-- packaging/
    +-- homebrew/
        +-- gitflow-cjs.rb
    +-- scoop/
        +-- gitflow-cjs.json
+-- docs/
    +-- dev-qa.md
+-- .gitattributes
+-- .shellcheckrc
+-- .editorconfig
+-- Makefile
+-- README.md
+-- LICENSE

Acceptance Criteria

• Project layout aligned with goals in README
• Structure is clear and documented
• Existing files/templates are preserved
• Ready for further refactor/rewrite tasks