[docs] fixed errors in aggs docs

- error in nested aggs example
- error in terms aggs example

docs/reference/search/aggregations/bucket/nested-aggregation.asciidoc

@@ -41,7 +41,7 @@ The following aggregations will return the minimum price products can be purchas
                 "path" : "resellers"
             },
             "aggs" : {
-                "min_price" : { "min" : { "field" : "nested.value" } }
+                "min_price" : { "min" : { "field" : "resellers.price" } }
             }
         }
     }

docs/reference/search/aggregations/bucket/terms-aggregation.asciidoc

@@ -134,7 +134,7 @@ Ordering the buckets by multi value metrics sub-aggregation (identified by the a
         "genders" : {
             "terms" : { 
                 "field" : "gender",
-                "order" : { "stats.avg" : "desc" }
+                "order" : { "height_stats.avg" : "desc" }
             },
             "aggs" : {
                 "height_stats" : { "stats" : { "field" : "height" } }