document error in week2 day5

[CNYuYang]

document：

The manifest format is like:

| JSON record | JSON record | JSON record | JSON record |

Again, note that we do not record the information of how many bytes each record has.

but mini-lsm/manifest.rs：

// record how many bytes each record has
file.write_all(&(buf.len() as u64).to_be_bytes())?;

so，The real format is：

| len,JSON record,crc | len,JSON record,crc | len,JSON record,crc | len,JSON record,crc |

[CNYuYang]

echo JSON objects must be separated by certain means.

[CNYuYang]

No problem. I made a mistake.