Update foreach Async arg description (#111)

plugins/foreach.go

@@ -12,7 +12,7 @@ import (
 type _ForeachPluginImplArgs struct {
 	Row     types.LazyExpr    `vfilter:"required,field=row,doc=A query or slice which generates rows."`
 	Query   types.StoredQuery `vfilter:"optional,field=query,doc=Run this query for each row."`
-	Async   bool              `vfilter:"optional,field=async,doc=If set we run all queries asynchronously (implies workers=1000)."`
+	Async   bool              `vfilter:"optional,field=async,doc=If set we run all queries asynchronously (implies workers=100)."`
 	Workers int64             `vfilter:"optional,field=workers,doc=Total number of asynchronous workers."`
 	Column  string            `vfilter:"optional,field=column,doc=If set we only extract the column from row."`
 }