MSC3550: Allow HTTP 403 as a response to profile lookups (#3550)
* add 403 proposal
* add msc number to file and filename
* correctly use markdown
* requested changes
* add links
* specify error code
* Update proposals/3550-allow-403-response-profile-lookup.md
Co-authored-by: Travis Ralston <travisr@matrix.org>
* fix formatting typo
Co-authored-by: Travis Ralston <travisr@matrix.org>
Co-authored-by: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>