test(docs): add docs topic runner

test/docs/runtests.jl

@@ -0,0 +1,16 @@
+# This file is a part of JuliaFEM.
+# License is MIT: see https://github.com/JuliaFEM/JuliaFEM.jl/blob/master/LICENSE.md
+
+using Test
+
+const SNIPPET = joinpath(@__DIR__, "..", "..", "docs", "src", "snippets", "minimal_elasticity_quickstart.jl")
+
+@testset "Documentation snippets" begin
+    @test isfile(SNIPPET)
+    include(SNIPPET)
+    r = minimal_elasticity_quickstart()
+    @test r.ndofs == 375
+    @test r.nnz_stiffness == 19773
+end
+
+include("readme_example.jl")