update README

README.md

@@ -1,20 +1,49 @@
 # ocrd_repair_inconsistencies
 
-Automatically re-order lines, words and glyphs to become textually consistent with their parents.
+    Automatically re-order lines, words and glyphs to become textually consistent with their parents.
+
+## Introduction
 
 PAGE-XML elements with textual annotation are re-ordered by their centroid coordinates
-in top-to-bottom/left-to-right fashion iff such re-ordering fixes the inconsistency
-between their appropriately concatenated `TextEquiv` texts with their parent's `TextEquiv` text.
+iff such re-ordering fixes the inconsistency between their appropriately concatenated
+`TextEquiv` texts with their parent's `TextEquiv` text.
+
+If `TextEquiv` is missing, skip the respective elements.
+
+Where available, respect the annotated visual order:
+- For regions vs lines, sort in `top-to-bottom` fashion, unless another `textLineOrder` is annotated.  
+  (Both `left-to-right` and `right-to-left` will be skipped currently.)
+- For lines vs words and words vs glyphs, sort in `left-to-right` fashion, unless another `readingDirection` is annotated.  
+  (Both `top-to-bottom` and `bottom-to-top` will be skipped currently.)
 
 This processor does not affect `ReadingOrder` between regions, just the order of the XML elements
 below the region level, and only if not contradicting the annotated `textLineOrder`/`readingDirection`.
 
 We wrote this as a one-shot script to fix some files. Use with caution.
 
+## Installation
 
-## Example usage
+(In your venv, run:)
+
+```sh
+make deps     # or pip install -r requirements.txt
+make install  # or pip install .
+```
+
+## Usage
+
+Offers the following user interfaces:
+
+### [OCR-D processor](https://ocr-d.github.io/cli) CLI `ocrd-repair-inconsistencies`
+
+To be used with [PageXML](https://github.com/PRImA-Research-Lab/PAGE-XML)
+documents in an [OCR-D](https://ocr-d.github.io) annotation workflow.
+
+### Example
+
+Use the following script to repair `OCR-D-GT-PAGE` annotation in workspaces,
+and then replace it with the output on success:
 
-For example, use this fix script:
 ~~~sh
 #!/bin/bash
 set -e