CSRF clarification

[birch-jayton]

Description:

• This PR covers #1329 and #1322.
• A good source for my changes is this portion of the MDN docs

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Please make sure that for your contribution:

• [ ] In case of a new Cheat Sheet, you have used the Cheat Sheet template.
• [x] All the markdown files do not raise any validation policy violation, see the policy.
• [x] All the markdown files follow these format rules.
• [ ] All your assets are stored in the assets folder.
• [ ] All the images used are in the PNG format.
• [x] Any references to websites have been formatted as [TEXT](URL)
• [x] You verified/tested the effectiveness of your contribution (e.g., the defensive code proposed is really an effective remediation? Please verify it works!).
• [ ] The CI build of your PR pass, see the build status here.

This PR covers issue #1329 This PR covers issue #1322