Packs are topical collections of plugins/modules/effects. Here is how you create a pack for sharing it as a contribution.

 PACKNAME\core (for managed .dlls)
 PACKNAME\core\x86 (for native 32bit .dlls)
 PACKNAME\core\x64 (for native 64bit .dlls)
 PACKNAME\factories
 PACKNAME\girlpower (for demo patches)
 PACKNAME\nodes*
 PACKNAME\nodes\effects (or \dx11, geom11, texture11 for DX11 effects)
 PACKNAME\nodes\modules
 PACKNAME\nodes\plugins

* The \nodes directory should include a nodelist.xml as explained here: nodelist (vvvv).

You can also set a version for your pack and create diffffs in case you want to change namings from one release to the next, see: Patch Conversions & Pack Versioning

And here is how to use a Pack.