the small content manager service of Google Sites, and link/host a file (javascript or txt) into blogger

If you want to upload and manage a .txt file with Google Sites,
then you will use  the small content manager service of GoogleSites.

two ways:
I) File cabinet
II) Attachments

I) File cabinet
select "create page" and "file cabinet" and you get this user interface to upload:

II) Attachments--------Step 1
create a new page (with the name "js") at the top level (you will use as a directory)
This page will be located at /site/NAMEofYourSite/js
click create page:

--------Step 2
go to manage site in the following menu:

--------Step 3

select "attachments"

and click the button "upload".

A window will appear (see below) and click "upload".

Choose "Select a different location" and click  js.

This user interface for the content management service is very bad, isn't?

--------Step 4

Then your file "NeonLightsText_noTag_js.txt" appears.

You can see the location, the size, the last update and the revision.

This part of  the content management service is better.

Click right on the download link and copy this link.

You have to clean this link (no https, and the end of your link must be .txt) 

in order to get this link:

"http://sites.google.com/site/javascript2blogger/js/NeonLightsText_noTag_js.txt"

--------Step 5

copy this link with script tag in your blogger gadget HTML/javascript (see below).

Then Blogger can use this content management service.

Rem: with yola.com , a free web hosting service (same of google-sites) has a better file management service.

You can also use yola for hosting you javascript file in the same way:

http://ex-ample.yolasite.com/js-notag.php