TODO.md

• Add SQUARE(n) macro
• Refactor the project into a nested project
• cio module for I/O as C string, i.e. null-terminated char array
  • stream_read_line function to read stream line by line
  • stream_read_all function to read all text from stream
  • cstring_read_line function to read C string line by line
• path module for file path cross Windows and Unix
  • base_name function to get base name of a file path
  • dir_name function to get directory name of a file path
  • ext_name function to get file extension of a file path