extract graph viewer in another repo without astro details

[volodymyrss]

e.g. here https://github.com/oda-hub/renku-graph-vis

astro details can still be in https://github.com/oda-hub/renku-graph-vis just in "example" directory or something, i.e. in a more modular way

also we'll need there a manual how to use and extend for new grphs

[burnout87]

https://github.com/oda-hub/renku-graph-vis/issues/3 https://github.com/oda-hub/renku-graph-vis/issues/2