Add mention of the CSV export in read-me

README.md

@@ -6,6 +6,7 @@ Scan directory and sub directories to display file layout from the size standpoi
 The package can optionally take a parameter which will be used as base directory.
 Otherwise the current directory is used.
 
+
 In the current path:
 
 ```sh
@@ -28,3 +29,14 @@ Less than 4K -> 377K (377699)
 Between 4K and 16K -> 168K (168241)
 ...
 ```
+
+## Export results
+
+Additionally the result is sent to a `fs-scan_output.csv`.
+Multiple run can be done from the same directory to collect outputs from multiple directories in a single file.
+
+```sh
+fs-scan dir1 && fs-scan dir2
+```
+
+CSV files are easy to use and import into spreadsheets.