Remove useless comment/TODO

babel.config.json:
comment was false, it was not a warning ignored when building
dependencies; but an option that babel expects to be at the same value
for these 3 plugins

cf this commit from mirador original repo : https://github.com/ProjectMirador/mirador/commit/c79d87885940c8c68447543ad6fb8b658a848dcc

AnnotationItem.js: cf issue #5