docs: fix incorrect return value in C usage section weibull/pdf

PR-URL: #10957

Reviewed-by: Philipp Burckhardt <pburckhardt@outlook.com>

Author: Om-A-osc

lib/node_modules/@stdlib/stats/base/dists/weibull/pdf/README.md

@@ -173,7 +173,7 @@ Evaluates the [probability density function][pdf] (PDF) for a [Weibull][weibull-
 
 ```c
 double out = stdlib_base_dists_weibull_pdf( 2.0, 1.0, 1.0 );
-// returns ~0.037
+// returns ~0.135
 ```
 
 The function accepts the following arguments: