README note about essence could be clearer

[Chealer]

The README's introduction contains the following note:

Note: pdAnnotate is no PDF viewer/ renderer. It provides an API to create different types of PDF annotations. For implementing a web-based PDF editor we recommend to use it in combination with PDF.js or a similar renderer.

This could be a little clearer. I suppose what it means is that pdfAnnotate does not provide a PDF annotation widget. I would suggest:

Note: pdfAnnotate is no PDF viewer/renderer. It provides an API to create different types of PDF annotations, but no user interface to use that interface or display the resulting annotations.