Add info label in customize allowlist / blocklist form

[SkyFoxCoder]

Fixes: #447

• Fixed a typo for consistency, in the form it is labelled: "Customize" and not "Customise"
• Adds the following label with a background to clarify what the check boxes are for (Image)

[tort-oise]

Great. PRs like these are what we need. I hope someone with write access returns soon.

[Nantris]

For me, saving the blocklist doesn't work. I used "Remove bloatware with custom blocklist" and everything was removed on Windows 11.

[SkyFoxCoder]

For me, saving the blocklist doesn't work. I used "Remove bloatware with custom blocklist" and everything was removed on Windows 11.

The list seems to be outdated compared to the non-GUI version.
That could explain why the blocklist isn't doing its job properly.

Create an issue if one doesn't already exists about that, since this is unrelated to that Pull Request.