Improve the qmk lint readme check (qmk#13941)

* improve lint readme check

* improve if

lib/python/qmk/cli/lint.py

@@ -4,7 +4,7 @@
 
 from qmk.decorators import automagic_keyboard, automagic_keymap
 from qmk.info import info_json
-from qmk.keyboard import keyboard_completer
+from qmk.keyboard import find_readme, keyboard_completer
 from qmk.keymap import locate_keymap
 from qmk.path import is_keyboard, keyboard
 
@@ -31,7 +31,8 @@ def lint(cli):
     ok = True
     keyboard_path = keyboard(cli.config.lint.keyboard)
     keyboard_info = info_json(cli.config.lint.keyboard)
-    readme_path = keyboard_path / 'readme.md'
+    readme_path = find_readme(cli.config.lint.keyboard)
+    missing_readme_path = keyboard_path / 'readme.md'
 
     # Check for errors in the info.json
     if keyboard_info['parse_errors']:
@@ -43,9 +44,9 @@ def lint(cli):
         cli.log.error('Warnings found when generating info.json (Strict mode enabled.)')
 
     # Check for a readme.md and warn if it doesn't exist
-    if not readme_path.exists():
+    if not readme_path:
         ok = False
-        cli.log.error('Missing %s', readme_path)
+        cli.log.error('Missing %s', missing_readme_path)
 
     # Keymap specific checks
     if cli.config.lint.keymap: