indicate in doc coordinates for affiliation

doc/Coordinates-in-PDF.md

@@ -14,7 +14,8 @@ Since April 2017, GROBID version 0.4.2 and higher, coordinate areas can be obtai
 * ```head``` for section titles,
 * ```s``` for optional sentence structure (the GROBID fulltext service must be called with the `segmentSentences` parameter to provide the optional sentence-level elements),
 * ```note``` for foot note elements,
-* ```title``` for the title elements (main article title and cited reference titles). 
+* ```title``` for the title elements (main article title and cited reference titles),
+* ```affiliation``` for the affiliation and address part.
 
 However, there is normally no particular limitation to the type of structures which can have their coordinates in the results, the implementation is on-going, see [issue #69](https://github.com/kermitt2/grobid/issues/69), and it is expected that more or less any structures could be associated with their coordinates in the orginal PDF.