Update beacon.md to reflect last changes

[sdelatorrep]

Update documentation so it reflects the last changes done to the spec (version number, add changes to the examples, add new parameters, etc.).
Notice that the examples are still showing v0.4 in apiVersion field.

[sdelatorrep]

Hi @teemukataja. Could you, please, update the beacon.md file with the changes introduced in v1.1.0 and examples of responses from your implementation? Thanks!

[sdelatorrep]

PR #279 fixes this.