some more little fixes and improvements #5

	name: whitespace_checks

	# Check whitespaces of the following file types
	# Not checked: .lua, .yml, .properties, .conf, .java, .py, .svg, .gradle, .xml, ...
	# (luacheck already checks .lua files)
	on:
	push:
	paths:
	- '**.txt'
	- '**.md'
	- '**.[ch]'
	- '**.cpp'
	- '**.hpp'
	- '**.sh'
	- '**.cmake'
	- '**.glsl'
	pull_request:
	paths:
	- '**.txt'
	- '**.md'
	- '**.[ch]'
	- '**.cpp'
	- '**.hpp'
	- '**.sh'
	- '**.cmake'
	- '**.glsl'

	jobs:
	trailing_whitespaces:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v4
	# Line endings are already ensured by .gitattributes
	- name: Check trailing whitespaces
	run: if git ls-files \| grep -E '\.txt$\|\.md$\|\.[ch]$\|\.cpp$\|\.hpp$\|\.sh$\|\.cmake$\|\.glsl$' \| xargs grep -n '\s$'; then echo -e "\033[0;31mFound trailing whitespace"; (exit 1); else (exit 0); fi

	tabs_lua_api_files:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v4
	# Some files should not contain tabs
	- name: Check tabs in Lua API files
	run: if grep -n $'\t' doc/lua_api.md doc/client_lua_api.md; then echo -e "\033[0;31mFound tab in markdown file"; (exit 1); else (exit 0); fi

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