Rename build command to consolidate and add a new command that runs consolidation & rendering

[endorama]

Each time I look at our provided instruction I get confused by the consolidate changelog command being called build. This is worse when explaining how the tool works because build seems a self contained command while in reality you still need to render the consolidated changelog to make it human readable.

Given this I think would be better if we renamed build to consolidate so that it reflect it's purpose and provide another command (build is a great name candidate, but we may want to call id differently to prevent confusion) that performs consolidation and rendering in one step.