Add menu entry to open active `.editorconfig` file

[ffes]

Basically the subject says it all. Add a menu entry to the plugin that opens the active .editorconfig file.

[eight04]

IIRC, there can be multiple configs apply to a single file.

[xuhdev]

Perhaps a menu option that expands to the list of all .editorconfig files.

[pryrt]

Maybe something like

... making the red text that I added either part of the normal dialog text (so three columns as shown), or as hover text for each property listed in the dialog box

Either way, that would allow us to see which file and which section of that file were contributing to which value for each property is in force (and thus see where to edit it).

Bonus feature: clicking the filename in the dialog or hover text to actually edit that .editorconfig
Bonus bonus feature: it not only opens the .editorconfig file, but scrolls to the right line in the file