[docs] use local mdoc (xamarin#1321)

Makefile

@@ -8,14 +8,14 @@ endif
 
 DOTNETPCL=$(MONOHOME)/xbuild-frameworks/.NETPortable/v4.5/Profile/Profile259/
 CORE=Xamarin.Forms.Core
-COREASSEMBLY=$(CORE)/bin/Release/$(CORE).dll
+COREASSEMBLY=$(CORE)/bin/Release/netstandard2.0/$(CORE).dll
 XAML=Xamarin.Forms.Xaml
-XAMLASSEMBLY=$(XAML)/bin/Release/$(XAML).dll
+XAMLASSEMBLY=$(XAML)/bin/Release/netstandard2.0/$(XAML).dll
 MAPS=Xamarin.Forms.Maps
-MAPSASSEMBLY=$(MAPS)/bin/Release/$(MAPS).dll
+MAPSASSEMBLY=$(MAPS)/bin/Release/netstandard2.0/$(MAPS).dll
 PAGES=Xamarin.Forms.Pages
-PAGESASSEMBLY=$(PAGES)/bin/Release/$(PAGES).dll
-MDOC=mono tools/mdoc/mdoc.exe
+PAGESASSEMBLY=$(PAGES)/bin/Release/netstandard2.0/$(PAGES).dll
+MDOC=mdoc
 
 docs: $(CORE).docs $(MAPS).docs $(XAML).docs $(PAGES).docs
 
@@ -32,16 +32,16 @@ $(PAGES).docs: $(PAGESASSEMBLY)
 	$(MDOC) update --delete -o docs/$(PAGES) $(PAGESASSEMBLY) -L $(DOTNETPCL)
 
 $(COREASSEMBLY): .FORCE
-	xbuild /property:Configuration=Release Xamarin.Forms.Core/Xamarin.Forms.Core.csproj
+	msbuild /property:Configuration=Release Xamarin.Forms.Core/Xamarin.Forms.Core.csproj
 
 $(XAMLASSEMBLY): .FORCE
-	xbuild /property:Configuration=Release Xamarin.Forms.Xaml/Xamarin.Forms.Xaml.csproj
+	msbuild /property:Configuration=Release Xamarin.Forms.Xaml/Xamarin.Forms.Xaml.csproj
 
 $(MAPSASSEMBLY): .FORCE
-	xbuild /property:Configuration=Release Xamarin.Forms.Maps/Xamarin.Forms.Maps.csproj
+	msbuild /property:Configuration=Release Xamarin.Forms.Maps/Xamarin.Forms.Maps.csproj
 
 $(PAGESASSEMBLY): .FORCE
-	xbuild /property:Configuration=Release Xamarin.Forms.Pages/Xamarin.Forms.Pages.csproj
+	msbuild /property:Configuration=Release Xamarin.Forms.Pages/Xamarin.Forms.Pages.csproj
 
 htmldocs: docs
 	$(MDOC) export-html -o htmldocs docs/*