Repeater: fix typos in cli options' help text

[dilyand]

Options and flags:
  (...)  
  --bufferSize <integer>
        Some failed inserts cannot be written to BigQuery, even after multiple attempts. These events are buffered and ultimately sunk to GCS.The buffer is flushed when uninsertableBufferSize is reached or when uninsertableTimeout passes.
    --timeout <integer>
        Some failed inserts cannot be written to BigQuery, even after multiple attempts. These events are buffered and ultimately sunk to GCS.The buffer is flushed when uninsertableBufferSize is reached or when uninsertableTimeout passes.
    --backoffPeriod <integer>
        Time (in seconds) to wait before trying to re-insert the record(s).
    (...)

Mismatch between option names and how they are referenced in the help text, eg bufferSize vs uninsertableBufferSize.

Also, technically Repeater does not try to re-insert records, but rather re-tries inserting them.