Hello!

Let me know if i should have opened this issue on the [pdfjs-dist](https://github.com/mozilla/pdfjs-dist) repo but I though here would fit.

I'm using pdfjs-dist and I'm in need of some more types to be exported. I have no idea how the types end up in the dist-repo but would love to open a PR if only someone could point me in the right direction 😃 Since I was using an older version of pdfjs-dist I realize the only type I need that's not in the type defs in the latest release are _PageViewport_ from _[display/display_utils](https://github.com/mozilla/pdf.js/blob/master/src/display/display_utils.js#L153)_.
expect(reason.message).toEqual(
          "The PDF file is empty, i.e. its size is zero bytes."
        );
      }
      await loadingTask.destroy();
    });
    it("checks that `docId`s are unique and increasing", async function () {
      const loadingTask1 = getDocument(basicApiGetDocumentParams);
      expect(loadingTask1 instanceof PDFDocumentLoadingTask).toEqual(true);
      await loadingTask1.promise;
      const docId1 = loadingTask1.docId;
      const loant(basicApiGetDocumentParams);
      expect(loadingTask2 instanceof PDFDocumentLoadingTask).toEqual(true);
      await loadingTask2.promise;
      const docId2 = loadingTask2.docId;
      expect(docId1).not.toEqual(docId2);
      const docIdRegExp = /^d(\d+)$/,
        docNum1 = docIdRegExp.exec(docId1)?.[1],
        docNum2 = docIdRegExp.exec(docId2)?.[1];
      expect(+docNum1).toBeLessThan(+docNum2);
      await Promise.all([loadingTask1.destroy(), loadingTask2.destroy()]);
    });
    it("creates pdf doc from PDF file with bad XRef entry", async function () {
      
      const loadingTask = getDocument(
        buildGetDocumentParams("PDFBOX-4352-0.pdf", {
          rangeChunkSize: 100,
        })
      );
      expect(loadingTask instanceof PDFDocumentLoadingTask).toEqual(true);