Add option to choose between GitHub/GitLab during template generation

[DominikCywinski]

Is your feature request related to a problem? Please describe.
When generating templates, I have to manually adjust CI files afterwards because GitHub and GitLab use different configurations (.github/workflows vs .gitlab-ci.yml) and different scripts rules.

Describe the solution you'd like
Add an interactive prompt: "Select Git platform: 1) GitHub 2) Gitlab" that generates the appropiate CI config files and platform-specific setup based on the choice

Additional context
For a temporary solution, I suggest swapping .github/workflows/ci.yml with .gitlab/ci.yml after template generation:

stages:
  - build
  - code-quality

build:
  stage: build
  image: python:3.13
  before_script:
    - curl -LsSf https://astral.sh/uv/install.sh | sh
    - source $HOME/.local/bin/env
  script:
    - uv sync
  only:
    - branches

code-quality-assurance:
  stage: code-quality
  image: python:3.13
  before_script:
    - curl -LsSf https://astral.sh/uv/install.sh | sh
    - source $HOME/.local/bin/env
  script:
    - uv sync --group code-quality
    - uv run ruff check
    - uv run ruff format --check
    - uv run ty check
  only:
    - branches