chore(otterdog): adding / updating file(s) due to blueprint default-security-policy

[eclipse-otterdog]

This PR has been created automatically by Otterdog due to the following blueprint: Ensures a default SECURITY.md file exists.

This will add a default security policy to the .github repository of the project. The created PR can be edited as needed to adjust to the project's needs.
If a repository defines a more specific SECURITY.md file it will take precedence over the one present in the .github repo.

[joakime]

This needs slightly different (updated) text before merging.