Update README.md (#25)

Update documentation #10

README.md

@@ -1,5 +1,7 @@
 Modpack - 3d Armor [0.4.13]
 ===========================
+![3d_armor screenshot](https://github.com/minetest-mods/3d_armor/blob/master/screenshot.png)
+
 
 ![](https://github.com/minetest-mods/3d_armor/workflows/luacheck/badge.svg)
 ![](https://github.com/minetest-mods/3d_armor/workflows/integration-test/badge.svg)