docs: update example in math/iter/special/sinpi to use iter/uniform

Migrate the example pseudorandom source from `@stdlib/random/iter/randu`
to `@stdlib/random/iter/uniform( 0.0, 2.0, ... )`, sampling across one
full period of `sin(πx)` rather than `[0, 1)`. The `uniform`-based
pattern is used by 88 of 97 (90.7%) sibling packages in
`math/iter/special`; the `(0.0, 2.0)` interval matches the period-2
cluster (`acovercos`, `acoversin`, `aversin`).

https://claude.ai/code/session_01CqGYLHLpXrp7baqtrMoRgx

Author: claude

lib/node_modules/@stdlib/math/iter/special/sinpi/README.md

@@ -95,11 +95,11 @@ The returned [iterator][mdn-iterator-protocol] protocol-compliant object has the
 <!-- eslint no-undef: "error" -->
 
 ```javascript
-var randu = require( '@stdlib/random/iter/randu' );
+var uniform = require( '@stdlib/random/iter/uniform' );
 var iterSinpi = require( '@stdlib/math/iter/special/sinpi' );
 
 // Create a seeded iterator for generating pseudorandom numbers:
-var rand = randu({
+var rand = uniform( 0.0, 2.0, {
     'seed': 1234,
     'iter': 10
 });

lib/node_modules/@stdlib/math/iter/special/sinpi/examples/index.js

@@ -18,11 +18,11 @@
 
 'use strict';
 
-var randu = require( '@stdlib/random/iter/randu' );
+var uniform = require( '@stdlib/random/iter/uniform' );
 var iterSinpi = require( './../lib' );
 
 // Create a seeded iterator for generating pseudorandom numbers:
-var rand = randu({
+var rand = uniform( 0.0, 2.0, {
 	'seed': 1234,
 	'iter': 10
 });