feat: add ast-grep (nvim-lua#177)

Author: chrisgrieser

lua/conform/formatters/astgrep.lua

@@ -0,0 +1,11 @@
+---@type conform.FileFormatterConfig
+return {
+  meta = {
+    url = "https://ast-grep.github.io/",
+    description = "A CLI tool for code structural search, lint and rewriting. Written in Rust",
+  },
+  command = "ast-grep",
+  args = { "scan", "--update-all", "$FILENAME" },
+  stdin = false,
+  exit_codes = { 0, 5 }, -- 5 = no config file exists
+}