Describe the packages as Chroma integrations, and complete the package READMEs - #3

• Package descriptions: they say Chroma, not ChromaDB. ChromaDotNet.Aspire.Hosting: "Aspire hosting integration for Chroma: a Chroma container in the AppHost.", ChromaDotNet.Aspire.Client: "Aspire client integration for Chroma and Chroma Cloud: a ChromaClient of ChromaDotNet.Client with health checks, traces and metrics.", both followed by "Built from the Chroma integration proposed to the Community Toolkit for Aspire, until it ships there. Community project, not affiliated with the .NET Foundation or Chroma." The tags and the icon are unchanged.
• Community project: the package READMEs and the README say that the project is a community project, not affiliated with the .NET Foundation, the Community Toolkit or Chroma.
• Client package README: the example has its using ChromaDB.Client;. The text names the Endpoint setting, says that HealthCheckTimeout is in milliseconds, which values win (connection string over settings, configureSettings over both), the health check names (Chroma, Chroma_{name} for a keyed client) and builder.AddConnectionString("chroma") in the AppHost.
• Hosting package README: the port of AddChroma, the connection string and the connection properties Host, Port and Uri, and the methods exported to TypeScript AppHosts, with a link to the example.
• README: where the package READMEs are, which files are synced from Add Chroma hosting and client integrations CommunityToolkit/Aspire#2219 and which belong to this repository, and how to build and test.

The folders synced from CommunityToolkit/Aspire#2219 are unchanged.