HDRP template tutorial text fixes

[iM0ve]

Fixed 3 issues regarding tutorial text:

1. In HDRP Settings 5/6 Frame Settings. Changed text from Camera > Lighting > Rendering to Camera > Rendering
2. Light Layers 3/4. Added a sentence explaining that Additional properties. The exact text is this: "If the property is not visible, enable Show Additional Properties using the 3 dots in the General section."
3. Reflection probe 4/5. Incorrect page was shown, a duplicate of page 5. I assigned the proper page 4.

Testing:
The PR should be safe, it only changes some text of the tutorials. I tested by opening the template and verifying that the tutorials I touched still work.

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