Add known issue for MacOS 14 _Float16 byte order detection issue (#4378)

release_docs/RELEASE.txt

@@ -1270,6 +1270,21 @@ Known Problems
     compilation to fail. This is due to a bug in libtool that was fixed in 2012
     and released in 2.4.4 in 2014.
 
+ -  When the library detects and builds in support for the _Float16 datatype, an
+    issue has been observed on at least one MacOS 14 system where the library
+    fails to initialize due to not being able to detect the byte order of the
+    _Float16 type (https://github.com/HDFGroup/hdf5/issues/4310):
+
+        #5: H5Tinit_float.c line 308 in H5T__fix_order(): failed to detect byte order
+        major: Datatype
+        minor: Unable to initialize object
+
+    If this issue is encountered, support for the _Float16 type can be disabled
+    with a configuration option:
+
+        CMake:      HDF5_ENABLE_NONSTANDARD_FEATURE_FLOAT16=OFF
+        Autotools:  --disable-nonstandard-feature-float16
+
  -  When HDF5 is compiled with NVHPC versions 23.5 - 23.9 (additional versions may
     also be applicable) and with -O2 (or higher) and -DNDEBUG, test failures occur
     in the following tests: