Clarify inbound token / allowlist functionality

What does this MR do?

In Slack, even people very close to this change were still confused about the wording here.

I made the following changes:

• Removed Control your project's job token scope – I believe this to be incorrect, as the setting does not change anything about the job token scope of the project on which you're editing the allowlist. It changes what the job tokens of other projects can do.
• Replaced its with their, because we are referring to multiple projects earlier in the sentence.
• In the For example sentence, I changed the order of project A and project B. While it is grammatically not as clean anymore, I think this is an okay tradeoff to avoid the reader having to juggle "why is something that is universally seen as option number 2 mentioned before option number 1" in their mind while parsing the entire example.
• Moved the "allowed project" term into brackets, as it was an additional thing you had to keep in mind/parse while trying to understand the example. Seeing project B first and then being told that it can be referred to differently is easier to grok than seeing a new term and then learning what the new term refers to.
• Replaced your current project with something that feels more specific and less open to misinterpretation to me.

Related issues

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