Refactor glidien_startup to separate out the code in heredoc sections
The heredoc format (here-document) allows a shell script to output content to a file (cat << EOF).
It is used in glidein_startup.sh because it is convenient: the file can be included without a separate download and extracted for others to use.
But the code is not so readable and lintable.
A better solution is to write the code in separate shell files and append them to glidein_startup.sh before shipping it.