Disambiguate the use of "store"

[agourlay]

We use the verb "store" quite extensively in our documentation.

It is however used with different semantics which can be confusing.

e.g. https://qdrant.tech/documentation/storage/#vector-storage

In-memory storage - Stores all vectors in RAM, has the highest speed since disk access is required only for persistence.

One way of reading this is that vectors are not persisted on disk, meaning that Qdrant would be an in-memory database.

In reality, vectors are stored on disk and are pre-loaded in RAM at startupfor fast access.

Ideally, it should be clear to the user whether something is persisted on disk and/or loaded in memory.

[davidmyriel]

I will transfer this over to landing_page and make sure terminology applies