Enhancement/Add viewer pane for source document #269
In many situations, users will use Doccano to annotate text that was extracted from documents such as PDF, Word or via OCR. Often times, the plain text extraction process will reduce the amount of information available to the annotator, e.g. loss of formatting, loss of page breaks, etc. Being able to view the source document during the annotation process therefore often is helpful to the annotator.
As such, this pull request adds a preview pane for PDF and Word documents to the annotation pane. The preview pane is toggled on the document level by adding the
In my opinion, annotators would really benefit from such a feature. However, it could even be better if we could have a "markdown like" way to record texts, so that displaying line breaks in a text might be possible (instead of a text + text preview)