added output

src/forth.gmo

@@ -34,6 +34,8 @@ for example, to convert a velocity to a pace, and print it:
 
 ``` input: 18, output: 3'20"
 18 vel>s1k .ms 
+
+output:
 3'20" ok
 ```
 
@@ -41,6 +43,8 @@ to do the opposite operation:
 
 ``` input: 3 20, output: 18 km/hr
 3 20 ms>s s1k>vel .vel
+
+output:
 18 km/hr ok
 ``` 
 
@@ -48,5 +52,7 @@ to get the pace of a given segment, using minutes, seconds and distance in meter
 
 ``` input: 1 03 300, output: 3'30"
 1 03 300 msd>s1k .ms
+
+output:
 3'30" ok
 ```