*: Use tabs for indentation where appropriate

I am a big supporter of the approach to indent with tabs and align with
spaces. (Read [here][1] f.e.) Thus at some places a simple `s/ {4}/\t/g`
(replace 4 with whatever fits) is not enough and a bit more thought is
needed. Because of that there are still places where I plan to
substitute the whitespace in the future.

This patch contains exclusively whitespace changes. Check for yourself
with `git diff --ignore-all-space`.

[1]: https://dmitryfrank.com/articles/indent_with_tabs_align_with_spaces

.config/polybar/scripts/vpn.sh

@@ -2,8 +2,8 @@
 
 connection="$(nmcli con show --active | awk '$3 ~ /^(vpn|tun)$/ { print $1 }')"
 if [ -n "$connection" ]; then
-    echo "VPN: $connection"
-    exit 0
+	echo "VPN: $connection"
+	exit 0
 fi
 
 # [o] is a hack to not grep the grep-command. See: