General restructure adding images and src folders
 Changes to be committed:
	modified:   git/0-preface.md
	renamed:    git/git-magic.pdf -> git/src/git-magic.pdf
	modified:   linux/scripts/automating-backups-with-tar-and-cron.md
	modified:   linux/scripts/replacing-values-in-files-using-perl-and-sed.md
	renamed:    linux/scripts/backup.cron -> linux/scripts/src/backup.cron
	renamed:    linux/scripts/replace_value.pl -> linux/scripts/src/replace_value.pl
	renamed:    linux/tools/top.png -> linux/tools/images/top.png
	modified:   linux/tools/monitoring-linux-systems.md
	deleted:    linux/tools/monitoring-linux-systems.md~
	modified:   programming/perl/processing-user-input-with-perl.md
	renamed:    programming/perl/user_input.pl -> programming/perl/src/user_input.pl