Add "Recovering from Task failure" page

Add a new page under https://docs.influxdata.com/influxdb/cloud/process-data/ giving an example of how to recover from task run failures by processing data in a range from the failed task(s) using `tasks.lastSuccess(orTime: -task.every)` rather than just the default range from `task.every`

##### Relevant URLs
- https://docs.influxdata.com/influxdb/cloud/process-data/
- https://docs.influxdata.com/flux/v0.x/stdlib/influxdata/influxdb/tasks/lastsuccess/