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/slapt-get.md

@@ -10,11 +10,11 @@
 
 - Install a package, or update it to the latest available version:
 
-`slapt-get --install {{package_name}}`
+`slapt-get --install {{package}}`
 
 - Remove a package:
 
-`slapt-get --remove {{package_name}}`
+`slapt-get --remove {{package}}`
 
 - Upgrade all installed packages to their latest available versions:
 
@@ -22,8 +22,8 @@
 
 - Locate packages by the package name, disk set, or version:
 
-`slapt-get --search {{package_name}}`
+`slapt-get --search {{query}}`
 
 - Show information about a package:
 
-`slapt-get --show {{package_name}}`
+`slapt-get --show {{package}}`