chore(home-manager): put neovim plugins configuration in a separate directory

modules/home-manager/cli/neovim/files/plugins/conform.lua

@@ -0,0 +1,12 @@
+require("conform").setup({
+  format_on_save = {
+    -- These options will be passed to conform.format()
+    timeout_ms = 500,
+    lsp_format = "never",
+  },
+  formatters_by_ft = {
+    yaml = {"yamlfmt"},
+    sh = { "shfmt" },
+    ["_"] = { "trim_whitespace" },
+  }
+})