Add "Credits" submenu

• https://github.com/jerrychong25/WIFIScannerApp
• https://gitlab.com/libeigen/eigen.git
• https://git.imp.fu-berlin.de/heisenberg/openwrt.git
• https://github.com/Rookfighter/least-squares-cpp.git
• https://github.com/mborgerding/bch_codec