Subplots layoute

[FedeClaudi]

Problem description

I'm not sure if AoG is the right place to do this or if it should be part of Makie or even a separate package.

Matplotlib (and gg plot in R I think) has this feature where you can pass a string specifying a figure layout:

mosaic = """
    AB
    CD
    """
fig = plt.figure()
axes = fig.subplot_mosaic(mosaic)

gives a figure with 4 subplots and changing mosaic e.g. to:

mosaic = ""'
AAABB
AAACC
"""

can be used to create more complicated layouts.

It's a very convenient way to specify a figure layout, it would be great to have something similar in Julia