nkf: add page (#2795)

pages/common/nkf.md

@@ -0,0 +1,28 @@
+# nkf
+
+> Network kanji filter.
+> Converts kanji code from one encoding to another.
+
+- Convert to UTF-8 encoding:
+
+`nkf -w {{path/to/file.txt}}`
+
+- Convert to SHIFT_JIS encoding:
+
+`nkf -s {{path/to/file.txt}}`
+
+- Convert to UTF-8 encoding and overwrite the file:
+
+`nkf -w --overwrite {{path/to/file.txt}}`
+
+- Set new line code to LF and overwrite (unix type):
+
+`nkf -d --overwrite {{path/to/file.txt}}`
+
+- Set new line code to CRLF and overwrite (windows type):
+
+`nkf -c --overwrite {{path/to/file.txt}}`
+
+- Decrypt mime file and overwrite:
+
+`nkf -m --overwrite {{path/to/file.txt}}`