Warn about routing with special chars /6

[Rick-Anderson]

Fixes #27900

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[Rick-Anderson]

@SchroterQuentin @ArthurHNL @DanielBryars @skovalyova @talshloman @celluj34 @thegrahamking please review and suggest better wording. I'm hoping to make this very visible so folks can find it before spending a lot of time debugging. Hopefully those who hit this problem will click on the GitHub issue and provide feedback so we can get a good idea how common this problem is.

[thegrahamking]

I've only observed the behaviour with /, so can only comment that that is correct. I suggest adding wording regarding workarounds e.g. use query string params

[Tratcher]

+ -> is form encoding, not url encoding, it shouldn't affect the path.

[ArthurHNL]

@Rick-Anderson Sorry for my late reply, I got quite sick over the weekend. But this change looks good. Thanks for clearing this up in the documentation.

[ArthurHNL]

@Rick-Anderson Sorry for my late reply, I got quite sick over the weekend. But this change looks good. Thanks for clearing this up in the documentation.

[Mosch0512]

i feel like : should also be documentet here?