Differentiate static and markdown files

.github/workflows/validate.yaml

@@ -88,22 +88,32 @@ jobs:
           import sys
 
           allowed_chars = re.compile(r'^[a-z0-9-\.+]+$')
+          allowed_chars_static = re.compile(r'^[a-z0-9-\._]+$') # images etc. may use the underscore
+
           content_dir = 'src/content'
           errors = []
           for root, dirs, files in os.walk(content_dir):
             for file in files:
               full_path = Path(root, file)
               if full_path.name == '_index.md':
                 continue
-              if not allowed_chars.match(full_path.stem):
-                errors.append(f"- {full_path}'\n")
+              if full_path.name == '_template.md.tpl':
+                continue
+              
+              if full_path.suffix.lower() == '.md':
+                if not allowed_chars.match(full_path.stem):
+                  errors.append(f"- FILE {full_path}'")
+              else:
+                # static files
+                if not allowed_chars_static.match(full_path.name):
+                  errors.append(f"- FILE {full_path}'")
 
             for dir in dirs:
               if not allowed_chars.match(dir):
-                errors.append(f"- {Path(root, dir)}'\n")
+                errors.append(f"- DIR {Path(root, dir)}'")
           
           if len(errors) > 0:
-            print("The following file/folder names use invalid characters. Only lowercase letters, digits, hyphens and period are allowed.\n\n")
+            print("The following file/folder names use invalid characters. Only lowercase letters, digits, hyphens and period are allowed.\n")
             for error in errors:
               print(error)
             sys.exit(1)