Feature request: chart for square size

[rootulp]

Context

Related to #51

Celestia blocks include a data square where the size of the square is a power of 2. The square size is dynamic and adjusts up or down to accomodate the amount of data (encoded into shares) in the block. Currently data squares span the range from 1 to 64.

Proposal

It would be useful to see a visualization of the square size over time. As blocks get more full of blobs, we expect the square size to approach 64. When blocks are empty, we expect the square size to be closer to 1.