Doc for BoundaryFunction

[Iddingsite]

Add doc for BoundaryFunction with a small usage example.

[luraess]

Thanks @Iddingsite for starting this doc addition. Maybe one could add a docstring for

Chmy.jl/src/BoundaryConditions/boundary_function.jl

Lines 46 to 52 in 26c92d4

	# Create a continuous or discrete boundary function
	# if discrete = true, the function has signature f(grid, loc, dim, inds...)
	# if reduce_dims = false, the boundary condition function accepts the same number of coordinates as the number of indices
	function BoundaryFunction(fun::Function; discrete=false, parameters=nothing, reduce_dims=true)
	RF = reduce_dims ? ReducedDimensions : FullDimensions
	discrete ? DiscreteBoundaryFunction{RF}(fun, parameters) : ContinuousBoundaryFunction{RF}(fun, parameters)
	end

and possibly briefly discuss the discrete vs continuous and maybe the reduce_dim bit(s). Test should have most of it.

[luraess]

Thanks @Iddingsite for starting this doc addition. Maybe one could add a docstring for

Addressed by #83

[utkinis]

Thanks @Iddingsite for the contribution! Looks good to me, merging...