Improve help text about aborting due to text

docs/errors.rst

@@ -22,6 +22,12 @@ As the error message suggests, your options are:
 -  ``ocrmypdf --skip-text`` to skip OCR and other processing on any
    pages that contain text. Text pages will be copied into the output
    PDF without modification.
+-  ``ocrmypdf --redo-ocr`` to scan the file for any existing OCR
+   (non-printing text), remove it, and do OCR again. This is one way
+   to take advantage of improvements in OCR accuracy. Printable vector
+   text is excluded from OCR, so this can be used on files that contain
+   a mix of digital and scanned files.
+
 
 Input file 'filename' is not a valid PDF
 ========================================

src/ocrmypdf/_pipeline.py

@@ -252,7 +252,8 @@ def is_ocr_required(page_context):
     elif pageinfo.has_text:
         if not options.force_ocr and not (options.skip_text or options.redo_ocr):
             raise PriorOcrFoundError(
-                "page already has text! - aborting (use --force-ocr to force OCR)"
+                "page already has text! - aborting (use --force-ocr to force OCR; "
+                " see also help for the arguments --skip-text and --redo-ocr"
             )
         elif options.force_ocr:
             log.info("page already has text! - rasterizing text and running OCR anyway")