Extend documentation about assets and secondary entry points

[csisy-bt4w]

Type of Issue

[ ] Bug Report
[x] Feature Request

Description

I was trying to copy assets from a secondary entry point and couldn't find why it does not work. Then I found this issue: #2030

Even if this will not be implemented, the documentation should state that the assets is only valid in the main entry point, and assets defined in secondary entry points will be ignored.

Affected documentations:

• Secondary Entry Points
• Copy Assets
• Managing assets in a library

Version Information

$ node_modules/.bin/ng-packagr --version
ng-packagr:            17.0.0
@angular/compiler:     17.0.4
rollup:                4.4.1
typescript:            5.2.2