[CX] Document keywords / tokens / characters that need to be escaped

file.txt contains:

use CouchbaseAnalytics;

create bucket multi_ple with {"bucket":"multiple_table_db_3673_simple_table_1","nodes":"127.0.0.1","password":""};

create shadow dataset m_123& on multi_ple;

connect bucket multi_ple;

Try curl command:

curl -s --data pretty=true --data format=CLEAN_JSON --data-urlencode statement@file.txt http://localhost:8095/analytics/service

{

	"requestID": "88c87793-5e7f-4b76-9ae9-b1e3a3b17a7c",

	"signature": "*",

	"errors": [{ 

	"code": "1",

	"msg": "Lexical error at line 3, column 28.  Encountered: \"&\" (38), after : \"\""

	}],

	"status": "fatal",

	"metrics": {

		"elapsedTime": "784.131µs",

		"executionTime": "570607.035687234s",

		"resultCount": "0",

		"resultSize": "0"

	}

}