More documentation around limits

[MarcoPolo]

This should cover @BigLep's questions here: #59 (review).

1. How to bypass limits
2. What are the default limits if I do nothing when constructing a ResourceManager (or even better as a user am I always forced to set a Limiter when constructing a ResourceManager thus need to think about this).
3. If I do always have to create a Limiter, is there a base LimitConfig I can use (and where is it)?
4. What does the code look like if I like everything about a base LimitConfig but then want to override one specific part of it.

And address the question here: #59 (comment)

It would be best if the documentation included testable examples

[BigLep]

There were questions in https://www.notion.so/pl-strflt/Guide-for-how-to-respond-to-resource-exhaustion-attacks-b10f55cc9a3d4917ae80c9b914e05e8c#f5d6b23e93d84946be400466f7560628 that may also be relevant:

What are the consequences of enabling tight resource limits?
What connections are getting killed?
What kind of errors will I see?
Does resource limiting make make a difference between honest peers and bad peers?

[MarcoPolo]

A lot of this is covered in PR #75