Update aggregation-introduction.po

Author: tomliugen

locale/zh/LC_MESSAGES/core/aggregation-introduction.po

@@ -20,7 +20,7 @@ msgstr ""
 # 19aacd425f00438dac9983a05264b733
 #: ../source/core/aggregation-introduction.txt:3
 msgid "Aggregation Introduction"
-msgstr ""
+msgstr "聚合简介"
 
 # edf76cd4db2d43e0a63362837dacf4f0
 #: ../source/core/aggregation-introduction.txt:9
@@ -31,6 +31,7 @@ msgid ""
 ":program:`mongod` instance simplifies application code and limits resource "
 "requirements."
 msgstr ""
+"*聚合*是泛指各种可以处理批量记录并返回计算结果的操作。MongoDB提供了丰富的聚合操作，"
 
 # 27f9370e5e8d42d3bee0e4ac1a9e7b83
 #: ../source/core/aggregation-introduction.txt:17