docs: fix missing decimals

Signed-off-by: Athan <[email protected]>

Author: kgryte

lib/node_modules/@stdlib/stats/base/dists/planck/mode/README.md

@@ -56,10 +56,10 @@ Returns the [mode][mode] of a Planck distribution with shape parameter `lambda`.
 
 ```javascript
 var v = mode( 0.1 );
-// returns 0
+// returns 0.0
 
 v = mode( 1.5 );
-// returns 0
+// returns 0.0
 ```
 
 If provided a shape parameter `lambda` is nonpositive or `NaN`, the function returns `NaN`.