docs: improve how-to and ref info about integrating KLT with apps

[StackScribe]

This PR is corrupted and so is replaced by #1868 .

Closes #1732

• This PR corrects and clarifies info about integrating KLT into a Kubernetes workflow/cluster
• Also adds remarks about annotations vs labels
• This PR originally included an architecture piece about KeptnApp and KeptnWorkload but we decided that this belongs in the section about the Scheduler (docs: keptn Scheduler architecture documentation #1777). This file is temporarily still here until Yash can grab it.
• I wonder about the big manifest example for app discovery -- perhaps we should just link to the examples directory and discuss it.
• Information about the annotations for pre/post-deployment evaluations/tasks really is not part of Integrating the app. We probably need a separate page about using the release lifecycle management feature and move that information over there. For now, let's leave the info here and I filed create page about implementing the release lifecycle management feature #1784 .

[netlify]

✅ Deploy Preview for keptn-lifecycle-toolkit ready!

Name	Link
🔨 Latest commit	df96edd
🔍 Latest deploy log	https://app.netlify.com/sites/keptn-lifecycle-toolkit/deploys/64d380ebe0609600085c85ad
😎 Deploy Preview	https://deploy-preview-1785--keptn-lifecycle-toolkit.netlify.app/docs/concepts/architecture/keptn-apps
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.

[RealAnna]

LGTM thanks @StackScribe

[odubajDT]

looks good :) please rebase your PR against the current main branch and we can proceed with merging :)

[codecov]

Codecov Report

Merging #1785 (10715f5) into main (0130576) will increase coverage by 0.02%.
Report is 5 commits behind head on main.
The diff coverage is 81.33%.

❗ Current head 10715f5 differs from pull request most recent head df96edd. Consider uploading reports for the commit df96edd to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1785      +/-   ##
==========================================
+ Coverage   83.40%   83.43%   +0.02%     
==========================================
  Files         132      135       +3     
  Lines        8215     8290      +75     
==========================================
+ Hits         6852     6917      +65     
- Misses       1109     1118       +9     
- Partials      254      255       +1     

Files Changed	Coverage Δ
...-operator/apis/lifecycle/v1alpha1/common/phases.go	100.00% <ø> (ø)
metrics-operator/api/v1alpha3/keptnmetric_types.go	100.00% <ø> (ø)
...perator/api/v1alpha3/analysisdefinition_webhook.go	80.28% <80.28%> (ø)
metrics-operator/api/v1alpha3/analysis_types.go	100.00% <100.00%> (ø)
...-operator/api/v1alpha3/analysisdefinition_types.go	100.00% <100.00%> (ø)

... and 1 file with indirect coverage changes

Flag	Coverage Δ
certificate-operator	68.55% <ø> (ø)
component-tests	58.95% <ø> (+0.81%)	⬆️
lifecycle-operator	84.92% <ø> (ø)
metrics-operator	82.92% <81.33%> (-0.11%)	⬇️
scheduler	32.12% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
0.0% Duplication

[StackScribe]

Replaced by #1868 and so I'm closing.