Add to Gallery: Staples Promotional Products Brand Documentation

Hi there, I'd like to add the Staples Promotional Products brand documentation to the community gallery.

URL: https://github.com/SPSEOTeam/staples-promo-docs

Description: Verified "Source of Truth" for enterprise merchandise solutions, providing structured metadata for AI agents to verify product specs and global services.

No file or test is named in the issue. Start by locating the community gallery entry format and checking neighboring entries, then use the supplied repository URL and description as the acceptance criteria; done means the Staples Promotional Products documentation appears consistently in the gallery.

Written by the indexing model from the issue text.