docs(observability): add OpenTelemetry export guide and group log export destinations - #3063

[vale] reported by reviewdog 🐶 [Vale.Spelling] Did you really mean 'backend's'? Raw Output: {"message":"[Vale.Spelling] Did you really mean 'backend's'?","location":{"path":"calico-enterprise/observability/opentelemetry.mdx","range":{"start":{"line":156,"column":9},"end":{"line":156,"column":18}}},"severity":"ERROR","code":{"value":"Vale.Spelling"}}

[vale] reported by reviewdog 🐶 [Vale.Spelling] Did you really mean 'backend's'? Raw Output: {"message":"[Vale.Spelling] Did you really mean 'backend's'?","location":{"path":"calico-enterprise/observability/opentelemetry.mdx","range":{"start":{"line":104,"column":66},"end":{"line":104,"column":75}}},"severity":"ERROR","code":{"value":"Vale.Spelling"}}

[vale] reported by reviewdog 🐶 [Vale.Spelling] Did you really mean 'openTelemetry'? Raw Output: {"message":"[Vale.Spelling] Did you really mean 'openTelemetry'?","location":{"path":"calico-enterprise/observability/archive-storage.mdx","range":{"start":{"line":262,"column":50},"end":{"line":262,"column":63}}},"severity":"ERROR","code":{"value":"Vale.Spelling"}}

[vale] reported by reviewdog 🐶 [Vale.Terms] Use 'YAML' instead of 'yaml'. Raw Output: {"message":"[Vale.Terms] Use 'YAML' instead of 'yaml'.","location":{"path":"calico-enterprise/observability/archive-storage.mdx","range":{"start":{"line":290,"column":73},"end":{"line":290,"column":77}}},"severity":"WARNING","code":{"value":"Vale.Terms"}}

[vale] reported by reviewdog 🐶 [Vale.Terms] Use 'DNS' instead of 'dns'. Raw Output: {"message":"[Vale.Terms] Use 'DNS' instead of 'dns'.","location":{"path":"calico-enterprise/observability/archive-storage.mdx","range":{"start":{"line":196,"column":229},"end":{"line":196,"column":232}}},"severity":"WARNING","code":{"value":"Vale.Terms"}}

[vale] reported by reviewdog 🐶 [Vale.Terms] Use 'DNS' instead of 'dns'. Raw Output: {"message":"[Vale.Terms] Use 'DNS' instead of 'dns'.","location":{"path":"calico-enterprise/observability/archive-storage.mdx","range":{"start":{"line":26,"column":32},"end":{"line":26,"column":35}}},"severity":"WARNING","code":{"value":"Vale.Terms"}}