Loading font data from external storage, such as TF card or SPIFLASH

[meibao-real]

Hello Firstly, u8g2 is a fantastic project. Sometimes we need to use custom font data, and using bdfconv can create custom font data, but!! when I have a lot of fonts data and the MCU's Flash capacity is small, so there's a problem. such as I ported u8g2 to Stm32f103c8t6, the Stm32f103c8t6 flash has 64kb, but the fonts data has 200kb or more..... So can that package the font data into Bin binary(or other?) and store it in external memory, such as TF card or SPIFLASH, and then read the binary data for font loading when needed such as ..

 // form tf card load some font data
uint8_t* diyfont = fontsloadformsd("xxxx.bin")
u8g2.SetFont(diyfont)

so , What should I do if possible ? thanks.