Add quotes to rcon.yaml password

[BongoEADGC6]

Quotes allow for special characters to be used in the password field for the rcon config yaml.

Context

• Allow or the use of special characters in rcon and admin passwords

Choices

• This is what yaml allows

Test instructions

Tested with and without special characters.

1. Set env vars
2. Run EOL text insertion
3. run rcon-cli to check errors

Checklist before requesting a review

• I have performed a self-review of my code
• I've added documentation about this change to the README. (Documentation shouldn't be required as there is no documentation stating a limitation.)
• I've not introduced breaking changes.

[Dashboy1998]

What special characters currently don't work?

• ADMIN_PASSWORD=sp!@#$%^*()!1-_=+[]{}`~:;<>,.?SPACE WORD

The above works in main now. Looks like &/\ don't work in either.

[thijsvanloef]

While this does not change the actual string in the file, this does resolve an uncaught shellcheck error: https://www.shellcheck.net/wiki/SC2086