coriolis: .p files update, and slight Releasing.md tweak about this.

docs/Releasing.md

@@ -175,8 +175,12 @@ Before you create a new install each time you should:
 1. Ensure the data sourced from coriolis.io is up to date and works:
     1. Update the `coriolis-data` repo. **NB: You will need 'npm' installed for
      this.**
+        1. `cd coriolis-data`
+        1. `git pull`
+        1. `npm install` - to check it's worked.
     1. Run `coriolis.py` to update `modules.p` and `ships.p`
     1. XXX: Test ?
+    1. `git commit` the changes to the repo and the `.p` files.
 1. Ensure translations are up to date, see [Translations.md](Translations.md).
 
 # Preparing to Package