Add C implementation for @stdlib/stats/base/dists/planck/logcdf

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---

Author: yuvimittal

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

@@ -174,6 +174,7 @@ The function accepts the following arguments:
 double stdlib_base_dists_planck_logcdf
 ( const double x, const double lambda );
 ```
+
 </section>
 
 <!-- /.usage -->
@@ -191,6 +192,7 @@ double stdlib_base_dists_planck_logcdf
 <section class="examples">
 
 ### Examples
+
 ```c
 #include "stdlib/stats/base/dists/planck/logcdf.h"
 #include <stdlib.h>
@@ -204,17 +206,17 @@ static int discrete_uniform( const int min, const int max ) {
 }
 
 int main( void ) {
-	double x;
-	double lambda;
-	double y;
-	int i;
-
-	for ( i = 0; i < 25; i++ ) {
-		x = discrete_uniform( 0, 40.0 );
-		lambda = random_uniform( 0.1, 5.0 );
-		y = stdlib_base_dists_planck_logcdf( x, lambda );
-		printf( "x: %lf, λ: %lf, ln(F(x;λ)): %lf\n", x, lambda, y );
-	}
+    double x;
+    double lambda;
+    double y;
+    int i;
+
+    for ( i = 0; i < 25; i++ ) {
+        x = discrete_uniform( 0, 40.0 );
+        lambda = random_uniform( 0.1, 5.0 );
+        y = stdlib_base_dists_planck_logcdf( x, lambda );
+        printf( "x: %lf, λ: %lf, ln(F(x;λ)): %lf\n", x, lambda, y );
+    }
 }
 ```