Setup Package Registry integrations with Templates
### Problem to solve
The GitLab Package Registry allows users to integrate with various package manager clients so they can build, publish and share packages, right from within GitLab. We currently offer support for Maven and npm, but will be adding support for several others, such as NuGet, Conan, rubygems, Linux.
We currently leave all of the setup to the user, who may struggle to configure and adopt the integrations due to that extra complexity.
### Intended users
- [Software Developer](https://design.gitlab.com/getting-started/personas#persona-sasha)
- [DevOps Engineer](https://design.gitlab.com/getting-started/personas#persona-devon)
- [Systems Administrator](https://design.gitlab.com/getting-started/personas#persona-sidney)
- [Security Analyst](https://design.gitlab.com/getting-started/personas#persona-sam)
### Proposal
We will create an easy way to configure and manage package manager integrations for our users.
### Further details
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### Permissions and Security
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### Documentation
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### Testing
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### What does success look like, and how can we measure that?
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### Links / references
issue