templates/ada: add install phase

templates/ada/flake.nix

@@ -20,7 +20,12 @@
           };
 
           buildPhase = ''
-            gprbuild
+            gprbuild thing
+          '';
+
+          installPhase = ''
+            mkdir -p $out/bin
+            mv thing $out/bin
           '';
         });
 

templates/ada/thing.adb

@@ -0,0 +1,6 @@
+with Ada.Text_IO; use Ada.Text_IO;
+
+procedure Thing is
+begin
+	Put_Line ("Hi Thing!");
+end Thing;