Update Getting Started

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Right now the [Getting Started](https://github.com/MaterialDesignInXAML/MaterialDesignInXamlToolkit#-getting-started) section in the README is a bit outdated.

People who are just getting started with this library are not likely to have all of the [dependencies needed](https://github.com/MaterialDesignInXAML/MaterialDesignInXamlToolkit/wiki/Compiling-From-Source) (latest version of VS, .NET Core, etc.) to compile the source code and demo application.

I am looking for people newer to this project to either comment or submit a PR with suggestions on how to improve this.

Some ideas to consider:
- Getting started section so that it is as simple as possible for someone new to the library.
- ~Consider including a link to my [examples repo](https://github.com/Keboo/MaterialDesignInXaml.Examples)~
- Consider moving up the link to the releases page with the pre-compiled demo app from the [See It In Action section](https://github.com/MaterialDesignInXAML/MaterialDesignInXamlToolkit#-see-it-action)
- Remove the [Source Code section](https://github.com/MaterialDesignInXAML/MaterialDesignInXamlToolkit?tab=readme-ov-file#building-the-source) and instead simply link over to the [wiki page](https://github.com/MaterialDesignInXAML/MaterialDesignInXamlToolkit/wiki/Compiling-From-Source)

Examinez les sections Getting Started, See It In Action et Building the Source du README, ainsi que la page wiki liée Compiling From Source. Mettez à jour les instructions de prise en main afin que les prérequis et la démo précompilée soient faciles à trouver, et assurez-vous que les instructions de compilation depuis les sources renvoient vers le wiki ; le travail est terminé lorsqu'une personne découvrant le projet peut suivre le parcours documenté sans informations de configuration obsolètes.

Rédigé par le modèle d'indexation à partir du texte de l'issue.