add limitation note in specs

Author: Jim-215-Fisher

doc/specs/stdlib_stats_distribution_normal.md

@@ -22,6 +22,8 @@ With two arguments, the function returns a normal distributed random variate N(l
 
 With three arguments, the function returns a rank one array of normal distributed random variates.
 
+Note: the algorithm used for generating normal random variates is fundamentally limited to double precision.
+
 ### Syntax
 
 `result = [[stdlib_stats_distribution_normal(module):rvs_normal(interface)]]([loc, scale] [[, array_size]])`

src/stdlib_stats_distribution_normal.fypp

@@ -1,7 +1,7 @@
 #:include "common.fypp"
 #:set RC_KINDS_TYPES = REAL_KINDS_TYPES + CMPLX_KINDS_TYPES
 module stdlib_stats_distribution_normal
-    use stdlib_kinds, only :: sp, dp, xdp, qp, int32
+    use stdlib_kinds, only : sp, dp, xdp, qp, int32
     use stdlib_error, only : error_stop
     use stdlib_random, only : dist_rand
     use stdlib_stats_distribution_uniform, only : uni=>rvs_uniform