Docs: Add new path for files on the panel-dashboard for Kirbytag (image: …)

[HeinerEF]

Issue with Reference

Please look at my last comment of getkirby/kirby#7355:

Files on the start page of the panel (the dashboard) are the so-called “global files” of the website, which can be referenced on each page with the path “<filename.ext>”,
e.g:
(image: new.gif)

If there is a file with the same name on the respective page, this file and NOT the global file with the same name will be used!!!

Note:
Under Kirby up to and including version 4.8 global files on other pages had to be called like this:
(image: /content/new.gif)
This change has to be considered when updating old Kirby versions to Kirby 5.x!

Expected

Add as third example at https://github.com/getkirby/getkirby.com/blob/main/content/docs/2_reference/1_text/0_kirbytags/0_image/reference-kirbytag.txt:

----start of insertion----

Image of a file at the the panel dashboard (image is saved as global file "/content/myawesomepicture.jpg")

(\image: myawesomepicture.jpg)

If there is a file with the same name on the respective page, this file and NOT the global file with the same name will be used!!!
----end of insertion----

Screenshots