Tweak @GlobalScope functions documentation overall

[Mickeon]

This PR is the equivalent of #67100 but for @GlobalScope. However, because the documentation is so large, I decided not to touch constants and limit myself. Indeed, it's not an exhaustive, complete series of tweaks, and may require a second pass at some point. One thing at the time.

Generally:

• Made use of [param] more frequently,
• Link to other classes' documentation more often.
• Improve and add more examples.
• Made the writing style closer to how the rest of the documentation is formatted.
• Ensure that multiple comments of an codeblock example are spaced out equally for better readability;
• Made the writing style closer to how the rest of the documentation is formatted;
• Ensure all of these are called "functions", not "methods". (methods are associated with objects, functions are not)
• Fixed a few typos.
• Touched up a few cases of zero being written as "zero" or "0" where "0" or "0.0" would be more appropriate.
• Removed mentions of "(real)". In 3.x, this was associated with floats, because TYPE_FLOAT was called TYPE_REAL.

More specifically:

• Every type-safe version of a function (such as ceili has a consistent final note ("A type-safe version of [method ceil], returning a [int]").
• Added more details to randomize, seed.
• Corrected floori()'s description. It's not the same as int(). This was not correct behavior and has been fixed.

[Mickeon]

I'm so incredibly dumb. I had the wrong title for this PR all along.

[mhilbrunner]

Brilliant PR, touching up a page that is looked at frequently (and often one of the first class ref pages users see).
All the changes make sense and look good to me, and the previous reviewers already spotted everything I noticed.

Great improvement and way more consistent, lets merge this - and thanks for taking care of this work! 🎉

[Mickeon]

Thank you very much for the kind words!