`LTeX` in `Legend`

[greimel]

In the README you say you can have LaTeX in the legend. Would you mind adding code for the example, just to get an idea of how hacky it is?

[asinghvi17]

The code is at https://gist.github.com/asinghvi17/53f09388954e8ad7728b85ecf62a20cf (it was adapted from some code written a couple of years ago, and still a little disjointed) but basically the principle was:

 ltexs = LTeX.(
     Ref(fig), [
         L"dv = 0", L"v", "Trajectories", "Trajectory from \$(v_0, w_0)\$",
         L"dw = 0", L"w", "Initial point"
     ];
     halign = :left,
 )
 translate!.(getproperty.(ltexs, :blockscene), 0, 0, 100)

 grid_indices = vcat(CartesianIndex.(1, 2:2:8), CartesianIndex.(2, 2:2:6))

 for (ind, ltex) in zip(grid_indices, ltexs)
     leg.grid[1, 1][ind[1], ind[2]] = ltex
 end

[asinghvi17]

P.S. The legend should be initialized with empty strings.

[asinghvi17]

I am pretty time squeezed now but will probably end up doing #27 and #29 at some point. With these, I'll be able to extend Makie's atomic text! to the tex-image recipe, which means you could just pass a CachedTeX or TeXDocument to the legend constructor, or possibly even axis ticks and labels!

[asinghvi17]

On current master (will tag a version today or tomorrow), you only have to supply LaTeXStrings to the legend (or TeXDocuments or CachedTeX) in place of ordinary Strings.