l10n: add font for Japanese

static/font/PixelMPlus/LICENSE_E

@@ -0,0 +1,16 @@
+M+ FONTS                                Copyright (C) 2002-2013 M+ FONTS PROJECT
+
+-
+
+LICENSE_E
+
+
+
+
+These fonts are free software.
+Unlimited permission is granted to use, copy, and distribute them, with
+or without modification, either commercially or noncommercially.
+THESE FONTS ARE PROVIDED "AS IS" WITHOUT WARRANTY.
+
+
+http://mplus-fonts.sourceforge.jp/mplus-outline-fonts/

static/font/SOURCES

@@ -1,2 +1,3 @@
 Monocraft:  https://idreesinc.itch.io/monocraft
-Pixeloid:   https://ggbot.itch.io/pixeloid-font
+Pixeloid:   https://ggbot.itch.io/pixeloid-font
+PixelM+:    https://itouhiro.hatenablog.com/entry/20130602/font