ArtifactHub, Project readme and pinned repo updates

[agardnerIT]

I didn't know where else this should live, so putting it here for the record.

I don't know who has access rights to change this stuff, so pinging some who might? @AloisReitbauer @AnaMMedina21 @thschue @bradmccoydev @DavidPHirsch @staceypotter

With the move from Keptn to Keptn (ie. Keptn to KLT which is being renamed Keptn), new "to fix" issues have been introduced:

1. The organisation readme still talks about event-driven things - this applies to Keptn v1 not "Keptn" so this whole "overview" section should be reworked.

2. "keptn" should probably be unpinned to avoid confusion and leave "lifecycle-toolkit" pinned

3. "kept.github.io" is still pinned and should probably be unpinned as the documentation is driven from the KLT repo now.

4. artifacthub still lists "keptn" and "klt". Twice this week someone has installed "keptn" thinking they were getting the lifecycle toolkit.

5. All keptn.sh links in the GitHub readme should instead be changed to lifecycle.keptn.sh/... links

6. "Integrations" link is no longer valid - these were integration for v1

7. The "project governance" link (which points here) is invalid and gives a 404.

8. Keptn sockshop is still linked and tells readers it for the "main demos". This is no longer true.

9. The spec repo should be unpinned or updated as it contains nothing for KLT and only has hte spec for v1.

10. https://tutorials.keptn.sh and hte associated repo can be retired with the move to KLT (in an attempt to avoid confusion between "Keptn" and "Keptn")

Edit: Found the readme: https://github.com/keptn/.github/tree/main/profile