Update some elements in BOM

[goalaleo]

Changes

• Update Source 1 link for top-camera and bottom-camera as it was still pointing to the v2/v3 camera store page.
• Add note for nozzle-rack to print it in white or light color filament as instructed in the printing parts documentation

Why

• Reduce likelyhood or a DIYer ordering the wrong camera when sourcing based on the bom_v4.0.0.html file
• Reduce likelyhood or printing the nozzle-rack in dark color

BEFORE: https://www.opulo.io/products/openpnp-usb-camera-set

AFTER: https://www.opulo.io/products/lumenpnp-v4-camera-set

[goalaleo]

@lucian151 @sphawes what would be the correct way to contribute to this repo as an outsider? I read the Making a Contribution section of the contributing doc, and based on it setting main as the base branch is not the way to go, but then there's this guideline

Individual contributors make changes in their forks, and merge them into the main repo's feature branch. Once the feature branch is done, it's then merged into master once it's complete

I can't create branches in the main repo, so then the question becomes: which feature branch in the main repo should I use, or should I ask one to be created? Or, for exampe, should one be automatically created for the next patch version?