This is a first pass, as this section could use further improvements for
both language and content. This should at least provide enough advice to
make use of the feature on amd64.
- Update list of required kernel options
- Mention that the GDB backend is disabled on stable and release branches
- Remove unneeded step (don't need to wait for kernel to trap again)
- Update the example the console outputs
- Some minor additions/improvements to wording