Lite font update experiment

all.lua

-- style.lua
-- First, I tried altering `style.lua` to add `fscale` attribute and a function to update style.
style.set_font = function()
  style.padding = { x = common.round(14 * style.fscale), y = common.round(7 * style.fscale) }
  style.divider_size = common.round(1 * style.fscale)
  style.scrollbar_size = common.round(4 * style.fscale)
  style.caret_width = common.round(2 * style.fscale)
  style.tab_width = common.round(170 * style.fscale)
  style.font = renderer.font.load(EXEDIR .. "/data/fonts/font.ttf", 14 * style.fscale)
  style.big_font = renderer.font.load(EXEDIR .. "/data/fonts/font.ttf", 34 * style.fscale)
  style.icon_font = renderer.font.load(EXEDIR .. "/data/fonts/icons.ttf", 14 * style.fscale)
  style.code_font = renderer.font.load(EXEDIR .. "/data/fonts/monospace.ttf", 13.5 * style.fscale)
end

style.fscale = SCALE
style.set_font()

-- view.lua
-- I modified view to add "zoom in", "zoom out" and "zoom reset" functionality
function View:zoom_in()
  style.fscale = style.fscale + 0.5
  style.set_font()
end

function View:zoom_out()
  style.fscale = style.fscale - 0.5
  style.set_font()
end

function View:zoom_base()
  style.fscale = SCALE
  style.set_font()
end

-- Keymap.lua
["ctrl++"] = "view:zoom_in",
["ctrl+-"] = "view:zoom_out",
["ctrl+0"] = "view:zoom_base"