fix: remove deprecated opt for conform.nvim (nvim-lua#1070)

- changed lsp_fallback -> lsp_format
- updated format_on_save function to reflect change above

Author: iton0

init.lua

@@ -806,7 +806,7 @@ require('lazy').setup({
       {
         '<leader>f',
         function()
-          require('conform').format { async = true, lsp_fallback = true }
+          require('conform').format { async = true, lsp_format = 'fallback' }
         end,
         mode = { 'n', 'v' },
         desc = '[F]ormat file or range (in visual mode)',
@@ -819,12 +819,17 @@ require('lazy').setup({
       --   -- have a well standardized coding style. You can add additional
       --   -- languages here or re-enable it for the disabled ones.
       --   local disable_filetypes = { c = true, cpp = true }
+      --   local lsp_format_opt
+      --   if disable_filetypes[vim.bo[bufnr].filetype] then
+      --     lsp_format_opt = 'never'
+      --   else
+      --     lsp_format_opt = 'fallback'
+      --   end
       --   return {
-      --     timeout_ms = 1000,
-      --     lsp_fallback = not disable_filetypes[vim.bo[bufnr].filetype],
+      --     timeout_ms = 500,
+      --     lsp_format = lsp_format_opt,
       --   }
       -- end,
-      format_on_save = false,
       formatters_by_ft = {
         -- You can use 'stop_after_first' to run the first available formatter from the list
         -- javascript = { "prettierd", "prettier", stop_after_first = true },