Fix warnings in docs

[schillic]

┌ Warning: failed to run `@example` block in src/man/faq.md:274-281
│ ```@example parallel
│ prob = @ivp(x' = Ax, x(0) ∈ ConvexHullArray(B))
│ sol = solve(prob, T=12.0, alg=GLGM06(δ=0.02));
│ plot!(sol, vars=(0, 2), c=:lightgreen, alpha=.5, lw=0.2, xlab="t", ylab="y")
│ 
│ import DisplayAs  # hide
│ DisplayAs.Text(DisplayAs.PNG(fig))  # hide
│ ```
│   value =
│    discretization not implemented for the given arguments: InitialValueProblem{ConstrainedLinearContinuousSystem{Float64, Matrix{Float64}, Universe{Float64}}, ConvexHullArray{Float64, BallInf{Float64, Vector{Float64}}}}(ConstrainedLinearContinuousSystem{Float64, Matrix{Float64}, Universe{Float64}}([0.0 1.0; -1.0 0.0], Universe{Float64}(2)), ConvexHullArray{Float64, BallInf{Float64, Vector{Float64}}}(BallInf{Float64, Vector{Float64}}[BallInf{Float64, Vector{Float64}}([1.0, 1.0], 0.1), BallInf{Float64, Vector{Float64}}([2.0, 2.0], 0.1), BallInf{Float64, Vector{Float64}}([3.0, 3.0], 0.1), BallInf{Float64, Vector{Float64}}([4.0, 4.0], 0.1), BallInf{Float64, Vector{Float64}}([5.0, 5.0], 0.1)])), `FirstOrderZonotope` approximation model with:
│        - exponentiation method: ReachabilityAnalysis.BaseExpAlg()
┌ Warning: no doc found for reference '[`normalize!`](@ref)' in src/lib/discretize.md.
┌ Warning: no doc found for reference '[`norm`](@ref)' in src/lib/discretize.md.
┌ Warning: no doc found for reference '[`normalize!(::Line, ::Real)`](@ref)' in src/lib/discretize.md.
┌ Warning: no doc found for reference '[`numrsets`](@ref)' in src/tutorials/taylor_methods/introduction.md.
┌ Warning: no doc found for reference '[`evaluate`](@ref)' in src/tutorials/taylor_methods/introduction.md.
┌ Warning: no doc found for reference '[`rsetrep`](@ref)' in src/tutorials/taylor_methods/introduction.md.
┌ Warning: 'Hybrid-systems' is not unique in src/man/inputs.md.
┌ Warning: no footnotes found for 'BEKS17' in src/man/faq.md.
┌ Warning: no footnotes found for 'v1' in src/man/faq.md.