try to support a single ignore expression

main.py

@@ -348,6 +348,8 @@ class TodoParser(object):
             if not filename_search:
                 continue
             curr_file = filename_search.group(0)
+            if self._should_ignore(curr_file):
+                continue
             curr_markers, curr_markdown_language = self._get_file_details(curr_file)
             if not curr_markers or not curr_markdown_language:
                 print(f'Could not check {curr_file} for TODOs as this language is not yet supported by default.')
@@ -604,6 +606,13 @@ class TodoParser(object):
             projects = list(filter(None, projects.split(',')))
         return projects
 
+    def _should_ignore(self, file):
+        ignore_pattern = os.getenv('INPUT_IGNORE', None)
+        if ignore_pattern:
+            if re.match(ignore_pattern, file):
+                return True
+        return False
+
 
 if __name__ == "__main__":
     # Create a basic client for communicating with GitHub, automatically initialised with environment variables.