Add golang private modules tutorial link

[LiamDotPro]

Please check if what you want to add to awesome-go list meets quality standards before sending pull request. Thanks!

Please provide package links to:

repo link (github.com, gitlab.com, etc): https://github.com/s0rg/decompose
pkg.go.dev:

coverage service link (codecov, coveralls, etc.):

Make sure that you've checked the boxes below that apply before you submit PR.
Not every repository (project) will require every option, but most projects should. Check the Contribution Guidelines for details.

• The package has been added to the list in alphabetical order.
• The package has an appropriate description with correct grammar.
• As far as I know, the package has not been listed here before.
• The repo documentation has a pkg.go.dev link.
• The repo documentation has a coverage service link.
• The repo documentation has a goreportcard link.
• The repo has a version-numbered release and a go.mod file.
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The repo has a continuous integration process that automatically runs tests that must pass before new pull requests are merged.

Continuous integration is used to attempt to catch issues prior to releasing this package to end-users.
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[phanirithvij]

How is this related to https://github.com/s0rg/decompose ?