update the doc for dump-segment tool when using jdk11+ (#15971)

* update the doc for dump-segment tool when using jdk11+

* update the style

* fix spell check error

docs/operations/dump-segment.md

@@ -36,6 +36,22 @@ java -classpath "/my/druid/lib/*" -Ddruid.extensions.loadList="[]" org.apache.dr
   --out /home/druid/output.txt
 ```
 
+If you use JDK 11 and above, you need to add the following additional parameters
+```
+--add-opens java.base/java.lang=ALL-UNNAMED
+--add-opens java.base/sun.nio.ch=ALL-UNNAMED
+```
+The following is an example
+
+```
+java --add-opens java.base/java.lang=ALL-UNNAMED --add-opens java.base/sun.nio.ch=ALL-UNNAMED \
+  -classpath "/my/druid/lib/*" \
+  -Ddruid.extensions.loadList="[]" org.apache.druid.cli.Main \
+  tools dump-segment \
+  --directory /home/druid/path/to/segment/ \
+  --out /home/druid/output.txt
+```
+
 ### Output format
 
 #### Data dumps