docs: Add Space

Author: oliversalzburg

packages/documentation/docs/sections/space.md

@@ -1,7 +1,15 @@
 # Space
 
-!!! info
+## Planet Buildings
 
-    This section is still pending being documented.
+When you enable a building, this building will be built if all of these are true:
 
-    Our goal is to provide a full documentation during the beta phase. Please check back soon.
+1. Less than **Max** buildings have already been built.
+
+1. _All_ of the resources required for the building to built are filled to **Trigger** of their stock capacity.
+
+1. _All_ of the resources required for the building to built are sufficiently available after considering configured **Stock** and **Consume**.
+
+## Start Missions
+
+The missions you select, will automatically started as soon as the required materials are available.