put image and counter into one div container

[TsXor]

before:

after:

This makes it easier to manipulate images with css.

For example, we can use flex container to make the manga display in 2 columns with this css applied:

.ml-images{
 display: inline-flex;
 align-content: flex-start;
 flex-flow: row wrap;
}
.ml-images>div{
 box-sizing: border-box;
 flex: 0 0 50%;
}

but this css doesn't work with the original script, and only makes counter larger.

[TsXor]

the second commit is added because this change breaks the refreshing feature (exactly, cancelling a refresh)