Added release notes for MxOnAzure 1.18 and MxInfra 1.20 changes - #11759

[vale] reported by reviewdog 🐶 [Mendix.HeadingTitleCase] Use title case capitalization for 'What is JIT?'. Raw Output: {"message": "[Mendix.HeadingTitleCase] Use title case capitalization for 'What is JIT?'.", "location": {"path": "content/en/docs/deployment/mx-azure/mx-azure-jit-requests.md", "range": {"start": {"line": 17, "column": 4}}}, "severity": "ERROR"}