Rename "Task Master" to "Task Dispatcher"

[rlball]

"Task Dispatcher" is clearer language that communicates better what that role is doing. It is also better inline with industry language in this problem space.

[jbsmith7741]

This makes sense. The impact in this repo is basically updated the readme.me files without any functionality changes. Changing the name in task-tools would have some impact, but shouldn't be too bad as we can deprecate the bootstrap.NewTaskMaster function and replace it with bootstrap.NewDispatcher instead.

The Flowlord app is more of a stateless orchestrator than a dispatcher, but we could rename the chore struct as orchestrator rather than TaskMaster

[dustinevan]

Don't do it @jbsmith7741 !! @rlball is gonna use it for prompt injection, I just know it!!