Update occ instructions page

[RichardPillay]

Describe the bug

Not a bug, but probably the best place to raise it is here.

In the documentation pages, the page https://memories.gallery/occ-commands/ covers the Google Takeout migration.

There is no indication that this migration ONLY works on files that have already been indexed. This leads to a frustrating waste of time for a new user, at a time when he is still figuring things out and and is most likely to give up. The index command is right there earlier in the same page, but as a new user, how would you know to connect the two?

Steps To Reproduce

No response

Platform

All irrelevant.

Screenshots

No response

Additional context

There is a warning relating to the migration command. I'd suggest putting a further note there to run the index occ command before the migrate.