chore: update markdown description

Author: Neerajpathak07

lib/node_modules/@stdlib/stats/base/dists/erlang/variance/README.md

@@ -171,7 +171,7 @@ for ( i = 0; i < 10; i++ ) {
 
 #### stdlib_base_dists_erlang_variance( k, lambda )
 
-Returns the variance for a erlang distribution with shape parameter `k` and rate parameter `lambda`.
+Returns the [variance][variance] of an [Erlang][erlang-distribution] distribution with parameters `k` (shape parameter) and `lambda` (rate parameter).
 
 ```c
 double y = stdlib_base_dists_beta_variance( 1.0, 1.0 );