Update and review cluster data table and link to

[bclaremar]

https://github.com/UPPMAX/UPPMAX-documentation/tree/main/docs/hardware

We keep this because it is easier to edit than in site vision.

• [ ] review Rackham
• [ ] review Snowy
• [ ] fill Bianca with content
• [x] link from Rackham docs/cluster_guides/rackham.md
• [x] link from Snowy docs/cluster_guides/snowy.md
• [ ] link from Bianca docs/cluster_guides/bianca.md

[bclaremar]

Storage may be interesting as well

[bclaremar]

I'll leave this over the summer but anyone can pick up this!