Project layout references

[bcomnes]

Add some discussion of project layout ideas:

• this is not a standard Go project layout golang-standards/project-layout#117
• https://laurentsv.com/blog/2024/10/19/no-nonsense-go-package-layout.html
• https://go.dev/blog/organizing-go-code
• https://eli.thegreenplace.net/2019/simple-go-project-layout-with-modules/
• https://rakyll.org/style-packages/
• https://peter.bourgon.org/go-best-practices-2016/#repository-structure
• this is not a standard Go project layout golang-standards/project-layout#117 (comment)