add note about PR 153

Author: wkliao

README.md

@@ -74,8 +74,8 @@ Northwestern University and Argonne National Laboratory.
 * [E3SM I/O kernel study](https://github.com/Parallel-NetCDF/E3SM-IO)
 * [Scorpio](https://github.com/E3SM-Project/scorpio), the I/O module of E3SM.
 * [PIO](https://github.com/NCAR/ParallelIO) - parallel I/O library at NCAR.
-* [WRF](https://github.com/wrf-model/WRF/tree/master/external/io_pnetcdf)
-  - Weather Research & Forecasting Model at NCAR.
+* [WRF](https://github.com/wrf-model/WRF/tree/master/external/io_pnetcdf) -
+  Weather Research & Forecasting Model at NCAR.
 
 
 ### Acknowledgements

sneak_peek.md

@@ -24,7 +24,9 @@ This is essentially a placeholder for the next release note ...
   + none
 
 * New constants
-  + none
+  + C macro NC_FillValue replaces _FillValue. This conforms with NetCDF4's
+    change in its version 4.9.3 release.
+    See [PR #153](https://github.com/Parallel-NetCDF/PnetCDF/pull/153).
 
 * New APIs
   + none
@@ -63,7 +65,7 @@ This is essentially a placeholder for the next release note ...
   + Fix `pnetcdf-config` of reflecting the installation path when installation
     is done by running command `make install DESTDIR=/alternate/directory`
     which prepends '/alternate/directory' before all installation names.
-    See [PR #145](https://github.com/Parallel-NetCDF/PnetCDF/pull/154).
+    See [PR #154](https://github.com/Parallel-NetCDF/PnetCDF/pull/154).
 
 * New example programs
   + C/flexible_bottom.c and C/vard_bottom.c - These two examples construct MPI