Couple updates/ Additional checks

[Tylerjet]

• Added a check for if backup_folder=. and exit while informing the user that the backup folder cannot be the root directory of /home/{username}/
• created a backup_path variable within script.sh as there were 5 plus areas where the same $HOME/$backup_folder was being used so having a variable that you only need to change once to change all of them seems better
• added some additional checks for proper file and folder removal after the backup is pushed
• improved git commands so that if adding an existing backup repository or deleting the backup folder entirely the repo can be properly reinitialized and pulled.
• add check for when backing up and entire folder ensure that /* is in the path or else cp -r will not correctly check the individual files.
• few minor adjustments i might be forgetting about but either was formatting, ensuring variables are enclosed in brackets , or that $backup_path is now used where $HOME/backup_folder was previously placed

[Staubgeborener]

The script won't detect a file without a file extension right now. We should wrap line 34 - 38 in another if statement like

if [[ ! -d "$path" ]]; then
  if [[ ! "$path" =~ \*$ && ! "$path" =~ /$ && ! -f "$path" && ! "$path" =~ \.[^.]+$ ]]; then
    path="$path/*"
  elif [[ ! "$path" =~ \$ && ! -f "$path" && ! "$path" =~ \.[^.]+$ ]]; then
    path="$path*"
  fi
fi

Or make the if statement even larger instead of wrapping it.

Example to reproduce (i put echo $file $backup_path in L49 for more verbose):

pi@mainsailos:~/klipper-backup $ touch /home/pi/printer_data/config/testfile
pi@mainsailos:~/klipper-backup $ cat .env
[...]
path_klipperdata=printer_data/config/testfile
[...]
backup_folder=config/klipperbackup
pi@mainsailos:~/klipper-backup $ ./script.sh
Klipper-backup is not up to date, consider making a git pull to update

cp: cannot stat '/home/pi/printer_data/config/testfile/*': Not a directory
/home/pi/printer_data/config/testfile/* /home/pi/config/klipperbackup

The script can't detect testfile as a file because it doesn't have any file extension at all, and so testfile becomes a directory /*: /home/pi/printer_data/config/testfile/*