Add XBC.1.6* to the editor's choice

[Outpfmance]

At present, XBC.1.6* is growing rapidly in South Australia, Victoria, Western Australia and other places, and has been exported to other countries. I think it is necessary to add this variant XBC* to better track it.

[Sinickle]

I think that XBC.1.6* is really incomparable to the rest of XBC* at the moment -- I'm refraining from adding fast lineages until they reach 1000 sequences, but I do want to add XBC* and XBC.1.6* once XBC.1.6* is at 1000 seqs!

[Outpfmance]

@Sinickle Now that the global number of sequences for XBC.1.6* has reached 1157, it is well over 1000, and it is time to add it!