Add to Setup Path Example to Engine README (#162115)

Added link to direct to engine setup and a path example.

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engine/README.md

@@ -1,5 +1,9 @@
 # Flutter Engine
 
+## Setting up the Engine development environment
+
+See [here](https://github.com/flutter/flutter/blob/master/engine/src/flutter/docs/contributing/Setting-up-the-Engine-development-environment.md#getting-the-source)
+
 ## `gclient` bootstrap
 
 Flutter engine uses `gclient` to manage dependencies.

engine/src/flutter/docs/contributing/Setting-up-the-Engine-development-environment.md

@@ -50,7 +50,7 @@ Clone the Flutter source code. As of late 2024, the engine source is part of the
 [Setup a `.gclient` file](../../../../../engine/README.md) in the repository
 root (the `flutter/flutter` repository root), and run `gclient sync`.
 
-The "Engine Tool" called `et` is useful when working with the engine. It is located in the [`engine/src/flutter/bin`](https://github.com/flutter/flutter/tree/0c3359df8c8342c8907316488b1404a216f215b6/engine/src/flutter/bin) directory. Add this to your `$PATH` in your `.rc` file.
+The "Engine Tool" called `et` is useful when working with the engine. It is located in the [`flutter/engine/src/flutter/bin`](https://github.com/flutter/flutter/tree/0c3359df8c8342c8907316488b1404a216f215b6/engine/src/flutter/bin) directory. Add this to your `$PATH` in your `.rc` file: e.g. on UNIX, using `export PATH=/path/to/flutter/engine/src/flutter/bin:$PATH`.
 
 ### Additional Steps for Web Engine