Note that this file hasn’t been updated in years and it’s not meant as a “stop every exploit” solution. It helps, though.

If you say it quickly enough it may sound plausible to some but this is not how battery technology works, as explained by @skilltheamps@feddit.de

Perhaps CryptPad fits your needs. It’s an open-source privacy-aware collaborative office suite and storage solution. It’s end-to-end encrypted, so even if it gets hacked no usable information is leaked.