fix: try to find the config file better

lua/chatgpt_nvim/config.lua

@@ -1,6 +1,7 @@
 -- lua/chatgpt_nvim/config.lua
--- Modified to load the config file from the git root of the currently opened file
--- If not in a git repository, fallback to current working directory
+-- Modified to:
+-- 1) Determine the Git root based on the currently opened file.
+-- 2) If no file is open or not in Git repo, fallback to current working directory.
 
 local M = {}
 local uv = vim.loop
@@ -8,19 +9,40 @@ local uv = vim.loop
 local ok_yaml, lyaml = pcall(require, "lyaml")
 
 local function get_project_root()
-  -- Attempt to find git root
-  local git_root = vim.fn.systemlist('git rev-parse --show-toplevel')
+  -- Get the directory of the currently opened file.
+  -- If no file is open, we fallback to current working directory.
+  local current_file = vim.fn.expand("%:p")
+  local root_dir
+
+  if current_file == "" then
+    -- No file opened, fallback to cwd
+    root_dir = vim.fn.getcwd()
+  else
+    -- Extract directory from current file path
+    local file_dir = current_file:match("(.*)/")
+    if not file_dir then
+      -- If something went wrong extracting the directory, fallback to cwd
+      root_dir = vim.fn.getcwd()
+    else
+      -- Attempt to find git root from the file's directory
+      -- We run git rev-parse with `cd` to the file's directory.
+      local cmd = string.format("cd %s && git rev-parse --show-toplevel 2>/dev/null", vim.fn.shellescape(file_dir))
+      local git_root = vim.fn.systemlist(cmd)
       if vim.v.shell_error == 0 and git_root and #git_root > 0 then
-    return git_root[1]
+        root_dir = git_root[1]
+      else
+        -- Not a git repo or failed to find git root, fallback to the file's directory
+        root_dir = file_dir
       end
-  -- Fallback to current working directory if git root not found
-  return vim.fn.getcwd()
+    end
+  end
+
+  return root_dir
 end
 
 local function get_config_path()
   local root = get_project_root()
-  local config_path = root .. "/.chatgpt_config.yaml"
-  return config_path
+  return root .. "/.chatgpt_config.yaml"
 end
 
 function M.load()