custom theme for each widget

[iuiu34]

#35

• simple developer mode instructions
• (kinda) generical way to declare theme args in each widget
  my knowledge in ts, is way less than py, i'll try to work on improve the generic methods
• color, background_color, size, font declared as themes in all widgets (backend & frontend)

questions

• (concept) do you like the overall "generic theme" idea of this PR?
  in case so
• (backend) is clean to have the args in each py function? or would be cleaner to define theme: dict?
• (frontend) is clean to call const {color, font, backgroundColor, size, primaryColor, textColor} = getTheme(props); every time? or would be better to move to theme=getTheme(props);?
• (random) why readme.md is lower case not upper?

[iuiu34]

which nomenclature do you follow for the naming?

for the theme, shall i inherit tsx ones? but map mixedCase to snake_case?

In particular,

• font_size
• color_primary
• color_text
• font_family
• color_bg_container