docs: update punctuation

Signed-off-by: Athan <kgryte@gmail.com>

Author: kgryte

lib/node_modules/@stdlib/blas/ext/base/gjoin/README.md

@@ -72,13 +72,13 @@ Note that indexing is relative to the first index. To introduce an offset, use [
 ```javascript
 var Float64Array = require( '@stdlib/array/float64' );
 
-// Initial array...
+// Initial array:
 var x0 = new Float64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ] );
 
-// Create an offset view...
+// Create an offset view:
 var x1 = new Float64Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element
 
-// Join elements...
+// Join elements:
 var str = gjoin( 3, '|', x1, 2 );
 // returns '2|4|6'
 ```