create a repo template for Galaxy instance toolkit management

[martenson]

similar to https://github.com/galaxyproject/galaxy-tool-repository-template but for live Galaxy instances -- manage update, install, uninstall

viable models:

• https://github.com/usegalaxy-no/usegalaxy-no-tools
• https://vimeo.com/572140451
• poster_GCC2021_GA_tool_installation (1).pdf