docs: elaborate eject docs

Author: filipesilva

docs/documentation/eject.md

@@ -3,7 +3,14 @@
 # ng eject
 
 ## Overview
-`ng eject` ejects your app and output the proper webpack configuration and scripts
+`ng eject` ejects your app and output the proper webpack configuration and scripts.
+
+This command uses the same flags as `ng build`, generating webpack configuration to match those
+flags.
+
+You can use `--force` to overwrite existing configurations.
+You can eject multiple times, to have a dev and prod config for instance, by renaming the ejected
+configuration and using the `--force` flag.
 
 ### Ejecting the CLI