core.detect returns None if many=False and no renderers are detected
Merge branch 'feat/api-changes' into dev
core.detect returns single handler by default
core.detect returns an instance by default
Fix static url
Update docs
Merge branch 'dev' of https://github.com/CenterForOpenScience/modular-file-renderer into dev
Merge pull request #61 from linse/feature/dev-improvements

Debug messages if something goes wrong, instead of just internal server ...
Update gitignore
Remove previewer files
Merge remote-tracking branch 'origin/dev' into dev
it is named player, not previewer