[skip ci] Improve `warn_on_records_fetched` documentation

- ‘dection’ -> ‘detection’

- ‘exceeds threshold’ -> ‘exceeds the threshold’

- Other minor improvements.

activerecord/lib/active_record/core.rb

@@ -96,10 +96,10 @@ def self.configurations
 
       ##
       # :singleton-method:
-      # Specify a threshold for the size of query result sets. If the
-      # number of records in the set exceeds threshold, a warning is
-      # logged. This should be used to identify queries which pull
-      # thousands of records, which may cause memory bloat.
+      # Specify a threshold for the size of query result sets. If the number of
+      # records in the set exceeds the threshold, a warning is logged. This can
+      # be used to identify queries which load thousands of records and
+      # potentially cause memory bloat.
       mattr_accessor :warn_on_records_fetched_greater_than, instance_writer: false
       self.warn_on_records_fetched_greater_than = nil
 

activerecord/lib/active_record/relation/record_fetch_warning.rb

@@ -5,9 +5,8 @@ module RecordFetchWarning
       # `config.active_record.warn_on_records_fetched_greater_than` is
       # set to an integer, if the number of records a query returns is
       # greater than the value of `warn_on_records_fetched_greater_than`,
-      # a warning is logged. This allows for the dection of queries that
-      # return a large number of records, which could cause memory
-      # bloat.
+      # a warning is logged. This allows for the detection of queries that
+      # return a large number of records, which could cause memory bloat.
       #
       # In most cases, fetching large number of records can be performed
       # efficiently using the ActiveRecord::Batches methods.