feat: add findIndex, findLastIndex, and indexOf to namespace

---
type: pre_commit_static_analysis_report
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    status: passed
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---

Author: kgryte

lib/node_modules/@stdlib/blas/ext/lib/index.js

@@ -54,6 +54,33 @@ setReadOnly( ns, 'base', require( '@stdlib/blas/ext/base' ) );
 */
 setReadOnly( ns, 'cusum', require( '@stdlib/blas/ext/cusum' ) );
 
+/**
+* @name findIndex
+* @memberof ns
+* @readonly
+* @type {Function}
+* @see {@link module:@stdlib/blas/ext/find-index}
+*/
+setReadOnly( ns, 'findIndex', require( '@stdlib/blas/ext/find-index' ) );
+
+/**
+* @name findLastIndex
+* @memberof ns
+* @readonly
+* @type {Function}
+* @see {@link module:@stdlib/blas/ext/find-last-index}
+*/
+setReadOnly( ns, 'findLastIndex', require( '@stdlib/blas/ext/find-last-index' ) );
+
+/**
+* @name indexOf
+* @memberof ns
+* @readonly
+* @type {Function}
+* @see {@link module:@stdlib/blas/ext/index-of}
+*/
+setReadOnly( ns, 'indexOf', require( '@stdlib/blas/ext/index-of' ) );
+
 /**
 * @name sum
 * @memberof ns