ROX-31489: Add Lightspeed integration docs

[mtodor]

Description

This PR is adding instruction on how to make integration of StackRox MCP server with OpenShift Lightspeed.

Changes:

• added documentation
• linked documentation from root project README
• (refactoring) Adjusted port in configurations from 8443 to 443, because that is set by default for Central service - https://github.com/stackrox/stackrox/blob/ce49939b44b24c7d410f933b8227045ee403365c/image/templates/helm/stackrox-central/templates/_central_endpoints.tpl#L5
• Removed .svc.cluster.local from outputs where service link is provided. Now we use only <svc-name>.<namespace>

Validation

• manually tested on dev cluster

[codecov-commenter]

Codecov Report

❌ Patch coverage is 50.00000% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 77.36%. Comparing base (78eb515) to head (779f4a0).
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
cmd/stackrox-mcp/main.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #27   +/-   ##
=======================================
  Coverage   77.36%   77.36%           
=======================================
  Files          26       26           
  Lines        1109     1109           
=======================================
  Hits          858      858           
  Misses        216      216           
  Partials       35       35           

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