Update readme

Change-Id: I6f1e9a34b3575e8917a11864b87ea1feab9a4409
diff --git a/README.md b/README.md
index eaae975..84369c9 100644
--- a/README.md
+++ b/README.md
@@ -48,6 +48,8 @@
 "WPD11/A00/00005","Wikipedia","http://de.wikipedia.org/wiki/Ang_Lee"
 ```
 
+With the first column being the textSigle (aka the document identifier),
+the second being the provider name and the third being the URL.
 These files can be gzipped as well.
 Then run the indexation with:
 
@@ -88,6 +90,19 @@
          kalamar-plugin-externalresources
 ```
 
+To index using docker, run
+
+```shell
+$ docker run \
+         --rm \
+         --network host \
+         -v ${PWD}/db/:/db/:z \
+         -v ${PWD}/data/:/data \
+         -v ${PWD}/.env:/.env \
+         korap/kalamar-plugin-externalresources \
+         data/data.csv.gz
+```
+
 ## License
 
 Copyright (c) 2023, [IDS Mannheim](https://www.ids-mannheim.de/), Germany<br>