pages/*, style-guide: update contents, fix Markdown (#10492)

* pages/*, style-guide: update pages, fix Markdown (commit 1)

* Update pages

* style-guide.de: update page

* Apply suggestions from code review

Co-authored-by: Lena <126529524+acuteenvy@users.noreply.github.com>

* Apply suggestions from code review

Co-authored-by: Lena <126529524+acuteenvy@users.noreply.github.com>

* pip3: remove search command

* rpm: update path placeholder

Co-authored-by: pixel <pixel+github@chrissx.de>

* Update pages/linux/pkgfile.md

Co-authored-by: Lena <126529524+acuteenvy@users.noreply.github.com>

---------

Co-authored-by: Lena <126529524+acuteenvy@users.noreply.github.com>
Co-authored-by: pixel <pixel+github@chrissx.de>

pages/linux/distrobox-export.md

@@ -6,7 +6,7 @@
 
 - Export an app from the container to the host (the desktop entry/icon will show up in your host system's application list):
 
-`distrobox-export --app {{package_name}} --extra-flags "--foreground"`
+`distrobox-export --app {{package}} --extra-flags "--foreground"`
 
 - Export a binary from the container to the host: