Re-organize author data

[kbaley]

Right now, author data is duplicated in at least five places:

• authors.yml: Used for author data on post pages and about us page
• speaking.yml: Hard coded author name for each event
• authorList.json: Used to generate a random author for the home page
• _authors folder: For /author/{author_id} page which I'm fairly certain is never linked anywhere (might be used as a template for the bio page though)
• bios folder: Individual bio pages

Should remove the duplication and have author info in one place

[kbaley]

authorList.json is now auto-generated.

Not sure we want to do anything about the bios folder. It's not really a duplication.

Still think we can delete the _authors folder completely but need to test locally first.

[kbaley]

Removed _authors folder. It was used by the hexo-multiauthor plugin which, in fact, we weren't actually using. The plugin has been removed as well.

[kbaley]

Had to revert. Previous change caused bios to 404. Need to investigate more. For future reference, make sure you do a hexo clean then a hexo generate to test. hexo serve will often work locally otherwise.