v0.3.3

MassInstallAction v0.3.3

Diff since v0.3.2

Merged pull requests:

• Add a sophisticated "maintenance" demo (#27) (@timholy)
• Add automated backup workflow (#31) (@SaschaMann)
• Fix indentation in Documenter workflow (#33) (@timholy)
• Check for an existing CI.yml file (#34) (@timholy)
• Fix the URL for the CompatHelper workflow file (#36) (@DilumAluthge)