Add credit

new

- Daijiro Fukuda
- Ryo Ichinose (from #658)
- Yasutaka Kumei (from #658)
- xfangfang

already in the list

- Takuro Ashie
- Yoshiki Shibukawa

CONTRIBUTORS.md

@@ -75,6 +75,7 @@ video tutorials.
  - Jason Francis
  - Gerald Franz
  - Mário Freitas
+ - Daijiro Fukuda
  - GeO4d
  - Marcus Geelnard
  - Gegy
@@ -104,6 +105,7 @@ video tutorials.
  - Charles Huber
  - Brent Huisman
  - Florian Hülsmann
+ - Ryo Ichinose
  - illustris
  - InKryption
  - IntellectualKitty
@@ -122,6 +124,7 @@ video tutorials.
  - Cameron King
  - Peter Knut
  - Christoph Kubisch
+ - Yasutaka Kumei
  - Yuri Kunde Schlesner
  - Rokas Kupstys
  - Konstantin Käfer
@@ -285,6 +288,7 @@ video tutorials.
  - Andy Williams
  - Joel Winarske
  - Richard A. Wilkes
+ - xfangfang
  - Tatsuya Yatagawa
  - Ryogo Yoshimura
  - Lukas Zanner