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/common/pip.md

@@ -6,7 +6,7 @@
 
 - Install a package (see `pip install` for more install examples):
 
-`pip install {{package_name}}`
+`pip install {{package}}`
 
 - Install a package to the user's directory instead of the system-wide default location:
 
@@ -14,11 +14,11 @@
 
 - Upgrade a package:
 
-`pip install --upgrade {{package_name}}`
+`pip install --upgrade {{package}}`
 
 - Uninstall a package:
 
-`pip uninstall {{package_name}}`
+`pip uninstall {{package}}`
 
 - Save installed packages to file:
 
@@ -26,7 +26,7 @@
 
 - Show installed package info:
 
-`pip show {{package_name}}`
+`pip show {{package}}`
 
 - Install packages from a file: