Nvim: restructure all plugins configuration

.config/nvim/after/available/airline.rc.lua

@@ -0,0 +1,5 @@
+vim.g.airline_theme = 'minimalist'
+vim.g.airline_powerline_fonts = 1
+vim.g.airline_stl_path_style = 'short'
+vim.g.airline_highlighting_cache = 1
+vim.g.airline#extensions#searchcount#enabled = 0