Add examples using distance with geography

Page could use additional clarity, examples, and sample code that does the most common thing: distance using geography. Evidence on web of man people struggling through learning this.

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#### Document Details

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* ID: c2dcf82b-f177-e91b-96a5-67f2f57bd6c4
* Version Independent ID: 89c0803f-570f-07a6-6dc2-285678712c86
* Content: [Spatial Data - EF Core](https://learn.microsoft.com/en-us/ef/core/modeling/spatial#nettopologysuite)
* Content Source: [entity-framework/core/modeling/spatial.md](https://github.com/dotnet/EntityFramework.Docs/blob/main/entity-framework/core/modeling/spatial.md)
* Product: **entity-framework**
* Technology: **entity-framework-core**
* GitHub Login: @bricelam
* Microsoft Alias: **avickers**