Just below the file browser/editor you will find the links to create new files and folderswithin the current folder

You can create
html pages (use this for most cases)
wml pages (usually AVOID this option)
plain text files (for css , script and text files

custom page templates

If you create a folder in the root (main) folder called
file_presets
you can add or create custom page templates in this folder

Those template pages will then be in the list of file types you can create
and a copy of that template with your chosen name will be created when selected