style: fix return annotation

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

Author: kgryte

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

@@ -150,7 +150,7 @@ Returns the [mode][mode] of a Planck distribution with shape parameter `lambda`.
 
 ```c
 double out = stdlib_base_dists_planck_mode( 0.1 );
-// returns ~0
+// returns 0.0
 ```
 
 The function accepts the following arguments: