add support to show the filename as title and some fixes

[lumean]

Hi @tuunit
I hope this time no merge conflicts ;-)

This is to add support of showing the filename in the toolbar.

• add documentation to fix toolbar button corruption issue when toolbar is too small, by increasing minwidth in javascript

GraphViewer.prototype.minWidth = 500;

• fix duplicate display of external graphs

test

![](https://raw.githubusercontent.com/jgraph/drawio-diagrams/dev/examples/kanban-examples.drawio)

test

You can see it overlaps the second test. Something leads to duplicate display of the content with the material theme and the javascript GraphViewer.processElements(), by adding reload() this was fixed for me. I'm by no means a javascript expert, so feel free to change if you have a better solution.