Update values-pt (Portuguese)

[TheLilUser]

Hi, I am new in this repo and I am Portuguese-native (from Brazil). Here I bring some of the small corrections on the translations and their respective details why they have been changed.

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⚙️ Changes

1. cantread: "Impossível" is correct, but not commonly used or recognised in prompt message translations from "cannot" or "unable", then "Não é possível" fits a lot better here. "Configurações" is commonly used because there's usually more than a setting.
2. script_1E00: To match with other strings, I've changed from "Latim Expandido Adicional" to "Expansão Adicional do Latim" that looks more polished.
3. script_3000: For more than a punctuation, we use "pontuações", as that Unicode block contains multiple CJK punctuations.
4. script_FE20: Translation doesn't seem to be right and doesn't fit with script_0300. "Marcas Combinantes do Meio" is a clean choice here.

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ℹ️ Additional informations

This is my very first contribution attempt here, then I decided to make just a few important changes into the values-pt file. I may submit other pull requests about diffs into the Portuguese file if this gets approved. If there's any additional change to be made, please let me know, any change request is welcomed.

I use UnicodePad at my daily routine to pick up characters that do not appear in my keyboard, then decided to check out the code for it.

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[Ryosuke839]

Thank you for contributing. Everything look good to me! (as a non Portuguese speaker)