[Sidebar Option to download BackUp/textFile marks] To be Able to download marks without going through the history tab

[JoyeuZe]

Is your feature request related to a problem? Please describe.
I had some issue with the addon auto backup, so I prefer to save every pages marks on my own by using the backup download button in the text marker menu. However it gets very frustrating in my workflow to always go back to the history page. Id like then an option to gain efficiency in my uses of Textmarker. Despite this minor inconvenience, I'd like to say Textmarker is the best tool to do research and organize myself. I'm very glad to have find your work. Thank you very much

Describe the solution you'd like
A configurable shortcut and/or an option in the sidebar to download all marks with the same option we have in the history context menu (only marks, marks with metadata, and so on..)

Describe alternatives you've considered
Im working on my own to bind a shortcut from tripodactyl (a vim like addOn for Firefox) so I could get there faster, but I thought it might interests others to have this option enable. Also I plan to maybe get my hands into the textmarker app to try to implement it myself, even though I haven't yet the courage to meddle in addons dev myself.

Additional context
Add any other context or screenshots about the feature request here.

[sambody]

I would also like to have a download link without having to go to History.

For example: a "download all this page's highlights" in the context menu, and/or in the main extension menu (the one that appears when clicking on the extension's button). It would be a time saver, as part of my workflow is to always download the highlights when I'm ready.

Thanks for a very useful extension.

This request is probably related to #97