general cleanup and expansion, pick other good photos
add references
add quotes about Sofia in Wikiquote
greatly expand History section to a separate article degree
expand Geography section, add climate information
clean up, expand and restructure Culture section
add other sections (such as Demographics, Sport, Communications and media, Tourism, Education)
create articles for notable Sofia-related topics to enrich general encyclopedic coverage (quarters and town regions, facilities and structures, landmarks, history of the city, notable figures and residents, etc.), expand other existing sections
substitute info table with a suitable and better template
