Update docs

Let's try this kind of approach where JuliaFEM.jl documentation
is collected from other packages. May work or then not.

docs/make.jl

@@ -3,6 +3,59 @@
 
 using Documenter, JuliaFEM
 
+"""
+    copy_docs(pkg_name)
+
+Copy documentation of some package `pkg_name` to `docs/src/pkg_name`,
+where `pkg_name` is the name of package. Return true if success, false
+otherwise.
+"""
+function copy_docs(pkg_name)
+    src = joinpath(Pkg.dir(pkg_name), "docs", "src")
+    if !isdir(src)
+        warn("Cannot copy documentation of package $pkg_name from $src: ",
+             "No such directory exists. (Is the package in REQUIRE of JuliaFEM?)")
+        return false
+    end
+    dst = joinpath(Pkg.dir("JuliaFEM"), "docs", "src", pkg_name)
+    cp(src, dst; remove_destination=true)
+    info("Copied documentation of package $pkg_name from $src succesfully.")
+    return true
+end
+
+"""
+    add_page!(part, page)
+
+Add new page to documentation. Part can be USER_GUIDE, DEVELOPER_GUIDE or
+PACKAGES. `page` is a string containing path to the page, or `Pair`
+where key is the name of the page and value is the path to the page.
+
+# Examples
+
+If page starts with `#`, i.e. having title, page is automatically included
+to documentation with that name:
+
+```julia
+add_page!(PACKAGES, "MyPackage/index.md")
+```
+
+Title can be changed using `Pair`, i.e.
+
+```julia
+add_page!(PACKAGES, "Theory" => "MyPackage/theory.md")
+```
+
+"""
+function add_page!(dst, src)
+    file = isa(src, Pair) ? src.second : src
+    if !isfile(joinpath(Pkg.dir("JuliaFEM"), "docs", "src", file))
+        warn("Cannot add page $file: no such file")
+        return false
+    end
+    push!(dst, src)
+    return true
+end
+
 #=
 if haskey(ENV, "TRAVIS")
     println("inside TRAVIS, installing PyPlot + matplotlib")
@@ -11,11 +64,52 @@ if haskey(ENV, "TRAVIS")
 end
 =#
 
+USER_GUIDE = []
+
+# Developer's guide is published in FEMBase.jl
+DEVELOPER_GUIDE = []
+if copy_docs("FEMBase")
+    add_page!(DEVELOPER_GUIDE, "FEMBase/mesh.md")
+    add_page!(DEVELOPER_GUIDE, "FEMBase/fields.md")
+    add_page!(DEVELOPER_GUIDE, "FEMBase/basis.md")
+    add_page!(DEVELOPER_GUIDE, "FEMBase/integration.md")
+    add_page!(DEVELOPER_GUIDE, "FEMBase/elements.md")
+    add_page!(DEVELOPER_GUIDE, "FEMBase/problems.md")
+    add_page!(DEVELOPER_GUIDE, "FEMBase/solvers.md")
+    add_page!(DEVELOPER_GUIDE, "FEMBase/postprocessing.md")
+    add_page!(DEVELOPER_GUIDE, "FEMBase/results.md")
+    add_page!(DEVELOPER_GUIDE, "FEMBase/materials.md")
+end
+
+# Let's construct here some description for packages
+PACKAGES = []
+
+if copy_docs("FEMQuad")
+    add_page!(PACKAGES, "FEMQuad/index.md")
+end
+
+if copy_docs("FEMBasis")
+    add_page!(PACKAGES, "FEMBasis/index.md")
+end
+
+if copy_docs("HeatTransfer")
+    add_page!(PACKAGES, "HeatTransfer/index.md")
+end
+
+# API documentation
+LIBRARY = ["api.md"]
+
+# Collect all together
+PAGES = []
+push!(PAGES, "Home" => "index.md")
+#push!(PAGES, "User's guide" => USER_GUIDE)
+push!(PAGES, "Developer's guide" => DEVELOPER_GUIDE)
+push!(PAGES, "Description of packages" => PACKAGES)
+#push!("API documentation" => LIBRARY)
+
 makedocs(modules=[JuliaFEM],
          format = :html,
+         checkdocs = :all,
          sitename = "JuliaFEM",
-         pages = [
-                  "Introduction" => "index.md",
-                  "Examples" => "examples.md",
-                  "API" => "api.md"
-                 ])
+         analytics = "UA-83590644-1",
+         pages = PAGES)