Update installation instructions for Monarc

[ruslanbaidan]

Added instructions to download and run the installation script for Monarc.

Generic requirements in order to contribute to MONARC:

• One Pull Request per fix/feature/change/...
• Keep the amount of commits per PR as small as possible: if for any reason, you need to fix your commit after the pull request, please squash the changes in one single commit (or tell us why not)
• Always make sure it is mergeable in the default branch
• Any major changes adding a functionality should be disabled by default in the configuration of MONARC

What does it do?

If it fixes an existing issue, please use GitHub syntax: #<IssueID>

Questions

• Does it require a DB change?
• Are you using it in production?

Release Type:

• Major
• Minor
• Patch