godot: add page (#2183)

pages/common/godot.md

@@ -0,0 +1,23 @@
+# godot
+
+> An open source 2D and 3D game engine.
+
+- Run a project if the current directory contains a `project.godot` file, otherwise open the project manager:
+
+`godot`
+
+- Edit a project (the current directory must contain a `project.godot` file):
+
+`godot -e`
+
+- Open the project manager even if the current directory contains a `project.godot` file:
+
+`godot -p`
+
+- Export a project for a given target (the target must be defined in the project):
+
+`godot --export {{target}}`
+
+- Execute a standalone GDScript file:
+
+`godot -s {{script.gd}}`