[AWS] Add instruction to use external mysql database for metadata and pipeline

[Jeffwan]

Currently, we use PersistVolume based mysql database for these projects and upgrade becomes a challenges. One solution is to use external mysql database to host data.

We already have a change kubeflow/community-distribution#906 here.

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[wdhorton]

I'm going to work on this issue

[sarahmaddox]

Thanks @wdhorton!

/assign @wdhorton

[sarahmaddox]

@wdhorton Did you make any progress on this doc update?

[wdhorton]

@sarahmaddox Sorry for the delay, I'm currently working on it and expect to have some docs written in the next couple of days

[jtfogarty]

/area docs
/priority p2

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.