Add missing reducer functions to where operator documentation

Author: ntanwar-sumo

docs/metrics/metrics-operators/where.md

@@ -12,10 +12,6 @@ You can use the `where` operator to filter out either entire time series, or ind
 ```sql
 where [VALUE BOOLEAN EXPRESSION | REDUCER BOOLEAN EXPRESSION]
 ```
-## Checking my PR:
-```sql
-_collector="ABC7" | where type="web"
-```
 Where:
 
 * `[VALUE BOOLEAN EXPRESSION]` is a value expression that operates on individual data points of a time series. For example,