Add capital

README.md

@@ -30,7 +30,7 @@ The best way to explore the data (i.e. the coverage, the zones metadata, the hie
 You can build cosmogony to extract the regions on your own.
 
 - #### Build
-Here are the necessary manual steps to build cosmogony:
+Here are the necessary manual steps to build cosmogony :
 ```bash
 curl https://sh.rustup.rs -sSf | sh    # intall rust
 apt-get install libgeos-dev            # install GEOS

src/lib.rs

@@ -37,6 +37,9 @@ pub fn is_admin(obj: &OsmObj) -> bool {
             &&
             rel.tags.get("admin_level").is_some()
         }
+        OsmObj::Node(ref node) => {
+                node.tags.get("capital").map_or(false, |v| v == "yes")
+        }
         _ => false,
     }
 }