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/pacstall.md

@@ -5,15 +5,15 @@
 
 - Search the package database for a package name:
 
-`pacstall --search {{package_name}}`
+`pacstall --search {{query}}`
 
 - Install a package:
 
-`pacstall --install {{package_name}}`
+`pacstall --install {{package}}`
 
 - Remove a package:
 
-`pacstall --remove {{package_name}}`
+`pacstall --remove {{package}}`
 
 - Add a repository to the database (only GitHub and GitLab are supported):
 
@@ -29,7 +29,7 @@
 
 - Display information about a package:
 
-`pacstall --query-info {{package_name}}`
+`pacstall --query-info {{package}}`
 
 - List all installed packages: