Minor formatting changes to the nkf cheatsheet.

cheat/cheatsheets/nkf

@@ -1,20 +1,29 @@
 # check the file's charactor code
 nkf -g test.txt
+
 # convert charactor code to UTF-8
 nkf -w --overwrite test.txt
+
 # convert charactor code to EUC-JP
 nkf -e --overwrite test.txt
+
 # convert charactor code to Shift-JIS
 nkf -s --overwrite test.txt
+
 # convert charactor code to ISO-2022-JP
 nkf -j --overwrite test.txt
+
 # convert newline to LF
 nkf -Lu --overwrite test.txt
+
 # convert newline to CRLF
 nkf -Lw --overwrite test.txt
+
 # convert newline to CR
 nkf -Lm --overwrite test.txt
+
 # MIME encode
 echo テスト | nkf -WwMQ
+
 # MIME decode
 echo "=E3=83=86=E3=82=B9=E3=83=88" | nkf -WwmQ