Fix explanation

docs/src/explanations/default_outage_values.md

@@ -1,9 +1,8 @@
 # Default values used for outage statistics
 
-When data is not available in a user-supplied `GeometricDistributionForcedOutage`
-supplemental attribute, then the outage rates default to a set of defaults defined
+When a system does not contain any `GeometricDistributionForcedOutage` supplemental attributes
+attached to any computers, then the outage rates default to a set of defaults defined
 in the [Default Outage Rates CSV](https://github.com/NREL-Sienna/SiennaPRASInterface.jl/blob/main/src/util/descriptors/outage-rates-ERCOT-modified.csv) based off of rates in ERCOT.
 
-For any remaining components not captured by the supplemental attributes or CSV,
-such as lines, renewables, and storage, the outage rates are 0 0 and will never
-fail.
+For any remaining components not captured by the CSV defaults, such as lines,
+renewables, and storage, the outage rates are 0 and will never fail.