continue doc 1.0 upgrade

Author: ArnoStrouwen

docs/make.jl

@@ -23,6 +23,7 @@ makedocs(
     authors="Chris Rackauckas",
     modules=[Symbolics,SymbolicUtils],
     clean=true, doctest=false, linkcheck = true,
+    warnonly = [:docs_block, :missing_docs, :cross_references],
     format = Documenter.HTML(assets = ["assets/favicon.ico"],
                              mathengine = mathengine,
                              canonical="https://docs.sciml.ai/Symbolics/stable/"),

docs/src/getting_started.md

@@ -328,6 +328,7 @@ a function via a sparse matrix. For example:
 using LinearAlgebra
 N = 8
 A = sparse(Tridiagonal([x^i for i in 1:N-1], [x^i * y^(8-i) for i in 1:N], [y^i for i in 1:N-1]))
+show(A)
 ```
 
 Now we call `build_function`: