Add RangeKeeper container infrastructure

[bernd2022]

Summary

• Add Bicep parameter files for RangeKeeper container instances (dev: beta tag, prd: latest tag)
• Change containerCPU type from int to string to support decimal values like 0.5
• Add rk to deploy.sh instance options
• Update README with RangeKeeper mount path and documentation

Notes

• RangeKeeper uses its own CI/CD pipeline for deployments (see DFXswiss/rangekeeper#14)
• Bicep templates provide the initial infrastructure (fileshare, container group skeleton)
• The containerCPU type change affects all existing HB parameter files (values migrated from 0.5 to "0.5")

Test plan

• Verify existing HB container deployments still work with string CPU values
• Verify deploy.sh lists rk as a selectable instance