talks: add joys and pains of a long lived codebase
Merge pull request #17 from Pondidum/long-lived-codebase

talks: add joys and pains of a long lived codebase
Added categories
Added the lengths of the talks (done by NameFILIP in pull request #16)
Added Media for Thinking the Unthinkable by Bret Victor
Fixed a typo