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/windows/pipwin.md

@@ -13,15 +13,15 @@
 
 - Install a package:
 
-`pipwin install {{package_name}}`
+`pipwin install {{package}}`
 
 - Uninstall a package:
 
-`pipwin uninstall {{package_name}}`
+`pipwin uninstall {{package}}`
 
 - Download a package to a specific directory:
 
-`pipwin download --dest {{path\to\directory}} {{package_name}}`
+`pipwin download --dest {{path\to\directory}} {{package}}`
 
 - Install packages according to `requirements.txt`: