Link to community directories in the README

Hi. The README currently points to the official MCP Registry for browsing servers. I run DReview (https://dreview.co), a free community directory (install configs per-client, categorized, no login required to browse) would a maintainer be open to a short "community directories" mention alongside the registry link? No worries if that's out of scope for this repo. I just wanted to ask directly rather than open an unsolicited PR.