Add tip to the Readme for using citar-open-entry-in-zotero with a manual install of Zotero

[jpggithub]

I suggest to add the following advice in the Opening reference entries section of the Readme:

For using citar-open-entry-in-zotero with a manual install of Zotero, you could need the following command in the shell (as a simple user):

xdg-mime default zotero.desktop x-scheme-handler/zotero

(found on https://forums.zotero.org/discussion/comment/359181/#Comment_359181)

I have searched for approximately 2 hours before finding the problem on my PC 😅

[bdarcus]

I'm not sure that specific a recommendation would be appropriate, given diverse platforms and installation methods?

But it could be included as an example for linux.

Care to submit a PR?

[jpggithub]

I’m not familiar with git and PR... I propose the following text that you can use for what you want without any problem.

Title: Accessing from citar to files in Zotero under Linux

If you have installed Zotero manually, there's a possibility that the following line won't work (replace "citekey" by a valid citekey of Zotero)

xdg-open "zotero://select/items/@citekey"

In that case, if you want to be able to open a file referenced in Zotero from citar, you have to launch the following command in a shell (as a simple user):

xdg-mime default zotero.desktop x-scheme-handler/zotero

After that, citar-open and citar-open-files will propose to open files for a given citekey as expected.