Fix Quickstart, missing character

[bluepuma77]

It seems the README.md "Quickstart" is not correct:

$ git clone https://github.com/ovh/debian-cis.git && cd debian-cis
$ cp debian/default /etc/default/cis-hardening
                    ^
$ sed -i "s#CIS_LIB_DIR=.*#CIS_LIB_DIR='$(pwd)'/lib#" etc/default/cis-hardening
                                                      ^

I also don't understand why "Quickstart" is using only a specific file, not bin/hardening.sh:

$ bin/hardening/1.1.1.1_disable_freevxfs.sh --audit-all

[ThibaultDewailly]

Hello, this PR shall fix the issue, as well as answer your question, I hope you find it clear