Compatibility docs are misleading

### Describe the issue or suggestion

The compatibility docs could use some work.

- The [definitions](https://learn.microsoft.com/en-us/dotnet/core/compatibility/categories) doc makes sense (although the title and slug don't match)
- [Rules of library changes](https://learn.microsoft.com/en-us/dotnet/core/compatibility/library-change-rules) doesn't make senes here. It should go wherever other API design docs are
- The [API Removal](https://learn.microsoft.com/en-us/dotnet/core/compatibility/api-removal) doc should be deleted. It makes it sound like we do that more commonly than we do. As far as I'm concerned, in the rare case we do this, it is very much case by case. The vast majority of breaking changes are not due to API removals.I consider this doc to be very misleading.

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#### Document Details

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* ID: c4b482b0-6dd1-42de-5389-5b0b47823402
* Version Independent ID: 79a4adc9-b2c9-68b7-669e-2bd8d2d44faf
* Platform ID: 72b8b17d-eaa9-70fc-a412-7c36f8830155
* Content: [.NET API changes that affect compatibility - .NET](https://learn.microsoft.com/en-us/dotnet/core/compatibility/library-change-rules)
* Content Source: [docs/core/compatibility/library-change-rules.md](https://github.com/dotnet/docs/blob/main/docs/core/compatibility/library-change-rules.md)
* Service: **dotnet-fundamentals**
* GitHub Login: @gewarren
* Microsoft Alias: **gewarren**