Update whatsnew with PR number and contributor name

Author: ishaan-arora-1

docs/sphinx/source/whatsnew/v0.15.1.rst

@@ -19,7 +19,7 @@ Bug fixes
   values (e.g. multi-day data with nighttime gaps). Edge positions with
   only one valid neighbor now correctly use that single delta value
   (Perez eqn 3) instead of halving it.
-  (:issue:`1847`, :pull:`xxxx`)
+  (:issue:`1847`, :pull:`2698`)
 * Fix a division-by-zero condition in
   :py:func:`pvlib.transformer.simple_efficiency` when ``load_loss = 0``.
   (:issue:`2645`, :pull:`2646`)
@@ -63,6 +63,7 @@ Maintenance
 
 Contributors
 ~~~~~~~~~~~~
+* Ishaan Arora (:ghuser:`ishaan-arora-1`)
 * Aman Srivastava (:ghuser:`aman-coder03`)
 * Rajiv Daxini (:ghuser:`RDaxini`)
 * Echedey Luis (:ghuser:`echedey-ls`)