Make stack traces legible

[MasonProtter]

Currently, if you encounter an error in a LegibleLambda, the printing in the stacktrace is still not legible:

julia> using LegibleLambdas

julia> g = @λ x -> x + 1
(x -> x + 1)

julia> g("hi")
ERROR: MethodError: no method matching +(::String, ::Int64)
Closest candidates are:
  +(::Any, ::Any, ::Any, ::Any...) at operators.jl:560
  +(::T, ::T) where T<:Union{Int128, Int16, Int32, Int64, Int8, UInt128, UInt16, UInt32, UInt64, UInt8} at int.jl:87
  +(::UniformScaling, ::Number) at /Users/mason/julia/usr/share/julia/stdlib/v1.6/LinearAlgebra/src/uniformscaling.jl:145
  ...
Stacktrace:
 [1] (::var"#1#2")(x::String)
   @ Main ./REPL[2]:1
 [2] (::LegibleLambda{var"#1#2"})(args::String)
   @ LegibleLambdas ~/.julia/packages/LegibleLambdas/wGhDT/src/LegibleLambdas.jl:44
 [3] top-level scope
   @ REPL[3]:1

I guess what is needed would be to improve the printing of typeof(::LegibleLambda) which means that we'd have to store the requisite printing information in the struct itself.