- Remove BoostToStdCoroutineSwitchPlan.md and BoostToStdCoroutineTaskList.md
working documents from the repo root; the rename script rewrites their
'rippled' references and the job fails on the resulting dirty tree.
- Reword two CoroTask.h comments to use 'xrpld'.
- Drop cspell words (cppcoro, gantt, Pratik, Mankawde) that existed only
for the removed documents.