docs/desktop: Rewrite some desktop app guides for Rocky Linux 10

[wsoyinka]

PR creates updated Desktop app content for Rocky Linux 10

[sspencerwire]

So just change this to ## A simple, modern audio player and "Decibels" will come down as the level 1 heading from the meta. To be clear, since this is a heading, I think you'll get the emphasis you need without the bold face on all of these, but I'll leave that up to you.

[sspencerwire]

Same here "File Shredder comes down from the meta as the level 1 heading and then just replace the Introduction with ## Permanently and securely delete files

[sspencerwire]

So again, "Decoder" comes down from the meta, and ## Scan and generate QR codes

[sspencerwire]

Rinse and repeat as before: "Screenshot" comes down from the meta as a level 1 heading, and ## Taking screenshots and recording screencasts in GNOME

[sspencerwire]

"Valuta" will come down from the meta. And then change the level 2 heading to ## Currency conversing on GNOME

[github-actions]

Test results for f94c303:

Number of broken URLs: 6

URL,RESULT,FILENAME
 http://your_ip,failed,guides/cms/mediawiki.md
 http://$(hostname):8080,failed,guides/repositories/pulp_fetch_upload.md
 http://fcron.free.fr/,failed,guides/automation/cronie.md
 https://ftp.gnu.org/gnu/tar/,failed,guides/backup/tar.md
 https://ftp.gnu.org/gnu/hello/hello-2.12.tar.gz,failed,labs/systems_administration_I/lab7-software_management.md
 https://repocompare.rockylinux.org,failed,release_notes/8_5.md