[Bug][Move Book] `signer` has `drop` ability, not `store`

[lshoo]

Hi!

When I was translating the Move Book to the Chinese version, I found that the descriptions about ability of signer in the abilities chapter are conflicting in two places, one says that signer has the store ability on line 52, another says that signer has the ability of store The drop capability on line 55 Then I looked at the source code of signer.move, which shows that signer only has drop ability。

I think store in L52 should be drop, is my understanding correct？

Thanks！

lshoo@MoveDAO

[geometryolife]

The signer really only has the drop ability.