rename pleniere app to plenary
models: rename Pleniere to Plenary
scrapper: rename Pleniere to Plenary
pleniere: improve h1 title
move plenary templats to plenary/
rename plenary urls
update-politube-db: s/pleniere/plenary
move pleniere.js to plenary.js
update-politube-db: add oldest plenaries first