Repository template for code repositories

This template contains the following:

• Default .editorconfig and .gitignore for .NET projects
• Dependabot GitHub Action to enable auto-merge for Dependabot PRs
• MarkdownSnippets GitHub Action
• An issue template to complete the repository configuration once the new repository has been generated
• CI GitHub Actions to build, run tests, and push tags to Feedz.io
• The included sample project defines item groups to produce NuGet packages