More icon descriptions (easy to implement)

[Let's Sekuhara!]

In the sidebar there is a key which explains what the various icons mean:

- All

- Downloading

- Completed

- Active

- Inactive

But I always see a couple of other icons which have no description.

One is a grey up arrow. Another is a red up arrow. And come to think of it, the green up arrow has no dedicated description either, which is strange since that's a common one and I assume it means "ready to upload" or something.

I am visiting the forums in search of what those other icons mean, and it occurred to me that even if I find the answer others may be confused by them as well, so I'm posting this as a feature request.