Globus Concepts content, & links to tutorials

[akkornel]

Some feedback from @kamchan:

For people who has barely heard of globus and wanted to know learn how the general concept works, should we have a line to mention globus basic tutorials https://docs.globus.org/how-to/

This is kindof a reminder that I still need to put in content for the "About Globus" page. There are probably a few scenario items that can come from this, as well.