You can install and setup windows.nvim with packer plugin manager using next snippet:
use { "anuvyklack/windows.nvim", requires = { "anuvyklack/middleclass", "anuvyklack/animation.nvim" }, config = function() vim.o.winwidth = 10 vim.o.winminwidth = 10 vim.o.equalalways = false require('windows').setup() end }