Fix 'endian(n)ess' typo.

doc/Type/IO/Handle.pod6

@@ -310,11 +310,11 @@ C<utf-8> and C<utf-16>.
 X<|utf16-le>X<|utf16-be>X<|utf16>X<|utf-16>
 
 Unlike utf8, utf16 has an
-endianess — either big endian or little endian. This relates to the ordering of
-bytes. Computer CPUs also have an endianess. Perl 6's C<utf16> format specifier
-will use the endianess of host system when encoding. When decoding it will look
-for a byte order mark and if it is there use that to set the endianess. If there
-is no byte order mark it will assume the file uses the same endianess as the host
+endianness — either big endian or little endian. This relates to the ordering of
+bytes. Computer CPUs also have an endianness. Perl 6's C<utf16> format specifier
+will use the endianness of host system when encoding. When decoding it will look
+for a byte order mark and if it is there use that to set the endianness. If there
+is no byte order mark it will assume the file uses the same endianness as the host
 system. A byte order mark is the codepoint U+FEFF which is ZERO WIDTH NO-BREAK
 SPACE. On C<utf16> encoded files the standard states if it exists at the start
 of a file it shall be interpreted as a byte order mark, not a U+FEFF codepoint.
@@ -325,7 +325,7 @@ writing a file and files created with the utf16 encoding will be able to be
 read on either big or little endian systems.
 
 When using utf16be or utf16le encodings a byte order mark is B<not> used. The
-endianess used is not affected by the host cpu type and is either big endian for
+endianness used is not affected by the host cpu type and is either big endian for
 utf16be or little endian for utf16le.
 
 In keeping with the standard, a 0xFEFF byte at the start of a file is interpreted