Documentation: Add documentation for `OPTION`

[ssttuu]

Description

As far as I can tell, the OPTION statement is completely undocumented in the public documentation. We should fix this.

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[Dhghomon]

@ssttuu There's a bit here in the export and import pages, as well as a mention in the book:

https://surrealdb.com/docs/surrealdb/cli/export#option-import-keyword

https://surrealdb.com/learn/book/chapter-14#import-and-export

What could be nice is a clarification of exactly what side effects don't take place: events and table views are mentioned, but in case there is anything else to note. Or a more general bit of content on how side effects work in general every time a query is performed.