DOC: milvus bulk_import data format

[garyfeng]

Milvus documentation for bulk_import is sparse. The csv file has to be of the following specs, which I found out by reverse engineering -- first use attu to generate some sample data, then do a query and save the file.

• comma delimited, but absolutely no spaces anywhere
• the vector must be a string with double quotation marks

book_id,word_count,book_intro
101,13,"[1.1,1.2]"
102,25,"[2.1,2.2]"
103,7,"[3.1,3.2]"
104,12,"[4.1,4.2]"
105,34,"[5.1,5.2]"

Then you can upload a file like this via the attu interface. Need to confirm this can be uploaded using the bulk_import() function.