'Searches' section does not describe significance/false alarm rate, other minor issues in the section

In the 'Online Pipelines' section there is some technical discussion of methods to produce false alarm rate but no general introduction or discussion of what it is or means.

I suggest to insert a paragraph just before the 'Modeled Searches' subheading.

E.g.

"Each search produces a series of candidate events time-stamped at or close to the estimated peak of GW strain amplitude (for binary merger candidates, this represents the time of merger). Events close to each other in time will be grouped together in a 'superevent'.
Each candidate event is assigned a ranking statistic value by the search pipeline that produced it: higher statistic values correspond to a higher probability of astrophysical (signal) as opposed to terrestrial (noise) origin. The statistical significance of a candidate produced by a given pipeline is quantified by its false alarm rate. This is the expected number of events of noise origin produced by the pipeline with a higher ranking statistic than the candidate, per second of time searched. Since each search pipeline has an independent method of generating and ranking events, and of estimating the noise background, the false alarm rates assigned for events in the same superevent will in general be different. For an alert to be sent automatically, we require at least one event to have a false alarm rate below the threshold (...)"

Part of this might belong elsewhere, but it's IMO really a search specific explanation.