Merge pull request cubefs#897 from mervinkid/mervinkid/fix_cn_in_en_d…

…ocumentation

Replaced Chinese content to English from EN documentation.

docs/source/csv/performance-volume.csv

@@ -3,7 +3,7 @@ FollowerRead,True,True,
 Capacity,10 GB,300 000 000 GB,
 Data Replica Number,3,3,
 Meta Replica Number,3,3,
-Data Partition Size,120 GB,120 GB,只是理论值上限 并不预分配空间
+Data Partition Size,120 GB,120 GB,Logical upper limit with no pre-occupied space.
 Data Partition Count,10,1500,
 Meta Partition Count,3,10,
 Cross Zone,False,False,