Update README.md

Remove branch mapping information from README files and spell-check them using Grammarly.

README.md

@@ -1,5 +1,5 @@
-[![Contributors](https://img.shields.io/github/all-contributors/alpacahq/alpaca-trade-api-csharp?logo=github)](https://github.com/alpacahq/alpaca-trade-api-csharp/blob/develop/CONTRIBUTORS.md)
-[![Build](https://github.com/alpacahq/alpaca-trade-api-csharp/workflows/Build%20and%20Release/badge.svg?branch=master)](https://github.com/alpacahq/alpaca-trade-api-csharp/actions)
+[![Contributors](https://img.shields.io/github/all-contributors/alpacahq/alpaca-trade-api-csharp?logo=github)](https://github.com/alpacahq/alpaca-trade-api-csharp/blob/main/CONTRIBUTORS.md)
+[![Build](https://github.com/alpacahq/alpaca-trade-api-csharp/workflows/Build%20and%20Release/badge.svg?branch=main)](https://github.com/alpacahq/alpaca-trade-api-csharp/actions)
 [![Codacy](https://img.shields.io/codacy/grade/7659cd4379964ef190a1088aa879350a?logo=codacy)](https://www.codacy.com/gh/OlegRa/Alpaca.Markets/dashboard?utm_source=github.com)
 [![Coverage](https://app.codacy.com/project/badge/Coverage/7659cd4379964ef190a1088aa879350a)](https://www.codacy.com/gh/OlegRa/Alpaca.Markets/dashboard?utm_source=github.com)
 [![Nuget](https://img.shields.io/nuget/dt/Alpaca.Markets?logo=NuGet)](https://www.nuget.org/stats/packages/Alpaca.Markets?groupby=Version)
@@ -47,30 +47,23 @@ namespace AlpacaExample
     }
 }
 ```
-4.  Replace `KEY_ID` and `SECRET_KEY` values with your data from the Alpaca dashboard.
-5.  Run the sample application using `dotnet run` command and check the output. You should see information about the current market timestamp and the times that the market will open and close next.
+4.  Replace the `KEY_ID` and `SECRET_KEY` values with your data from the Alpaca dashboard.
+5.  Run the sample application using the `dotnet run` command and check the output. You should see information about the current market timestamp and when the market will open and close next.
 
-See the [UsageExamples](../../tree/develop/UsageExamples) project for near-to-real-world strategy implementation using this SDK and the [Alpaca.Markets.Tests](https://github.com/OlegRa/Alpaca.Markets.Tests) repository for SDK usage examples. The [Wiki](https://github.com/alpacahq/alpaca-trade-api-csharp/wiki) pages contain a lot of additional information about different aspects of this SDK (environments handling, authentication types, different order placement approaches, streaming client subscriptions handling, etc.).
+See the [UsageExamples](../../tree/main/UsageExamples) project for near-to-real-world strategy implementation using this SDK and the [Alpaca.Markets.Tests](https://github.com/OlegRa/Alpaca.Markets.Tests) repository for SDK usage examples. The [Wiki](https://github.com/alpacahq/alpaca-trade-api-csharp/wiki) pages contain a lot of additional information about different aspects of this SDK (environments handling, authentication types, different order placement approaches, streaming client subscriptions handling, etc.).
 
 ## Alpaca Data API subscription plans
 
-Alpaca provides 3 different subscription plans for the Data API v2 real-time streaming data: Free, Unlimited, and Business. The first one provides only IEX data and has some subscription limits. Other plans provide full SIP data without data subscription limits. The `IAlpacaDataStreamingClient` interface and its implementation from SDK provide unified access for both streams.
+Alpaca provides three different subscription plans for the Data API v2 real-time streaming data: Free, Unlimited, and Business. The first one offers only IEX data and has some subscription limits. Other plans provide complete SIP data without data subscription limits. The `IAlpacaDataStreamingClient` interface and its implementation from SDK provide unified access for both streams.
 
-Use the `Environments.Paper.GetAlpacaDataStreamingClient(...)` factory method for creating a client connected to the Free IEX data stream. For the Unlimited and Business SIP data stream use the `Environments.Live.GetAlpacaDataStreamingClient(...)` code. So _Paper_ environment for free data tier and _Live_ for paid subscriptions.
-
-## Mapping between branches and SDK versions
-
-| Branch                                       | Version | Description                                  | Milestone                |
-| -------------------------------------------- | ------- | -------------------------------------------- |--------------------------|
-| [develop](../../tree/develop)                | 8.x     | Unstable - experimental, can contain bugs    | [SDK 8.x WIP](https://github.com/alpacahq/alpaca-trade-api-csharp/milestone/18) |
-| [master](../../tree/develop)                 | 7.x     | LTS - good choice for the new development    | [SDK 7.x LTS](https://github.com/alpacahq/alpaca-trade-api-csharp/milestone/17) |
+Use the `Environments.Paper.GetAlpacaDataStreamingClient(...)` factory method to create a client connected to the Free IEX data stream. Use the `Environments.Live.GetAlpacaDataStreamingClient(...)` code for the Unlimited and Business SIP data stream. So _Paper_ environment for free data tier and _Live_ for paid subscriptions.
 
 ### Build instructions
 
-1.  Install the latest version of the [.NET 9.0 SDK](https://dotnet.microsoft.com/download) for your OS.
+1.  Install your OS's latest version of the [.NET 9.0 SDK](https://dotnet.microsoft.com/download).
 2.  Clone the local version of this repository or your fork (if you want to make changes).
 3.  Build the packages using the `dotnet build` command running in the root directory of the cloned repo.
 
 ## Contributors
 
-Thanks a lot for all the contributors. See the full list of project supporters in the [CONTRIBUTORS](https://github.com/alpacahq/alpaca-trade-api-csharp/blob/develop/CONTRIBUTORS.md) file.
+Thanks a lot for all the contributors. See the complete list of project supporters in the [CONTRIBUTORS](https://github.com/alpacahq/alpaca-trade-api-csharp/blob/main/CONTRIBUTORS.md) file.