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/stack.md

@@ -5,7 +5,7 @@
 
 - Create a new package:
 
-`stack new {{package_name}} {{template_name}}`
+`stack new {{package}} {{template}}`
 
 - Compile a package:
 
@@ -25,4 +25,4 @@
 
 - Run a program and pass an argument to it:
 
-`stack exec {{program_name}} -- {{argument}}`
+`stack exec {{program}} -- {{argument}}`