refactor: improve writable views

[danibix95]

Pull Request Type

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Documentation content changes
• Other... Please describe:

Description

This PR provides a review of "Writable Views" functionality, such that:

• main functionality has been revised
• multi-lookup (one-to-many relationships) definition has been fixed and an example can now be found in the docs
• the feature's documentation has been rewritten to better clarify the use case of it

PR Checklist

• The commit message follows our guidelines included in the CONTRIBUTING.md
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

Does this PR introduce a breaking change?

• Yes
• No