Adding collateral files in our new Help online

Hello All

LibreOffice new Help system enabled the already existing <object>
element that allows to open objects in the HTML help page. Objects can
be: embedded or external videos, audio, and also files with specific
MIME types.

From LibreOffice 6.1 and beyond, the help system now has support for
collateral files to help user in understanding the textual description
of the current page.

For example, a collateral file on pivot table will for sure help a new
user to start working with this powerful feature.

The documentation and L10N project invites you to help in two way:
* help us to translate some of these collateral files
* create meaningful collateral files in all areas of LibreOffice

A wiki page with much more details is available here, to give guidelines
for this new feature.

https://wiki.documentfoundation.org/Documentation/CollateralFiles

Please have a good reading on the wiki page and let's work to make our
help pages more user friendly.

Regards