Create formatter.lua

Black formatting added

lua/custom/plugins/formatter.lua

@@ -0,0 +1,15 @@
+return {
+    "jose-elias-alvarez/null-ls.nvim",
+    event = { "BufReadPre", "BufNewFile" },
+    dependencies = { "mason.nvim" },
+    opts = function()
+      local nls = require("null-ls")
+      return {
+        sources = {
+          nls.builtins.formatting.black.with({
+             extra_args = {"--line-length=120", "--skip-string-normalization"},
+          }),
+        },
+      }
+    end,
+}