docs(vscode): update README links and style (#857)

Author: alestiago

extensions/vscode/README.md

@@ -1,4 +1,3 @@
-[![Dart Frog Logo][logo_white]][dart_frog_link_dark]
 [![Dart Frog Logo][logo_black]][dart_frog_link_light]
 
 This is the [Dart Frog](https://dartfrog.vgv.dev/) [VS Code](https://code.visualstudio.com/) extension, which provides tools for effectively managing Dart Frog projects.
@@ -7,7 +6,7 @@ Developed with 💙 by [Very Good Ventures][very_good_ventures_link] 🦄
 
 ## Installation
 
-Dart Frog can be installed from the [VS Code Marketplace](https://marketplace.visualstudio.com/vscode) or by [searching within VS Code](https://code.visualstudio.com/docs/editor/extension-gallery#_search-for-an-extension).
+Dart Frog can be installed from the [VS Code Marketplace](https://marketplace.visualstudio.com/items?itemName=VeryGoodVentures.dart-frog) or by [searching within VS Code](https://code.visualstudio.com/docs/editor/extension-gallery#_search-for-an-extension).
 
 ## Commands
 
@@ -21,12 +20,10 @@ Dart Frog can be installed from the [VS Code Marketplace](https://marketplace.vi
 
 ## Demonstration
 
-![demonstration](https://github.com/VeryGoodOpenSource/dart_frog/blob/main/extensions/vscode/assets/new-route-middleware-usage.gif)
+![demonstration](https://raw.githubusercontent.com/VeryGoodOpenSource/dart_frog/main/extensions/vscode/assets/new-route-middleware-usage.gif)
 
 [ci_link]: https://github.com/VeryGoodOpenSource/dart_frog/actions/workflows/main.yaml
-[dart_frog_link_dark]: https://github.com/verygoodopensource/dart_frog#gh-dark-mode-only
-[dart_frog_link_light]: https://github.com/verygoodopensource/dart_frog#gh-light-mode-only
+[dart_frog_link_light]: https://github.com/verygoodopensource/dart_frog
 [license_link]: https://opensource.org/licenses/MIT
-[logo_black]: https://raw.githubusercontent.com/VeryGoodOpenSource/dart_frog/main/assets/dart_frog_logo_black.png#gh-light-mode-only
-[logo_white]: https://raw.githubusercontent.com/VeryGoodOpenSource/dart_frog/main/assets/dart_frog_logo_white.png#gh-dark-mode-only
+[logo_black]: https://raw.githubusercontent.com/VeryGoodOpenSource/dart_frog/main/assets/dart_frog_logo_black.png
 [very_good_ventures_link]: https://verygood.ventures