Use external style sheets instead of custom CSS being put in <style> tags in the header

[travis-jeans]

Custom BearBlog CSS appears to be inserted inside <style> </style> tags for every page in the header. This is inefficient and not a good use of HTML file space. Instead the content inside the custom CSS "Edit theme CSS" on the Nav dashboard page should be exported to a file (e.g. style.css) then referenced on each HTML page. e.g. <link rel='stylesheet' href='./style.css'>

I think doing this would be in line with BearBlog's minimalist and low-kilobyte philosophy while improving the readability of the output HTML files.