docs: improve READMEs (#1020)

### Summary of Changes

* Add a demo GIF
* Add more content to the README of the VS Code extension

docs/README.md

@@ -5,7 +5,10 @@
 [![codecov](https://codecov.io/gh/Safe-DS/DSL/branch/main/graph/badge.svg?token=ma0ytglhO1)](https://codecov.io/gh/Safe-DS/DSL)
 [![Documentation Status](https://readthedocs.org/projects/safe-ds-dsl/badge/?version=stable)](https://dsl.safeds.com)
 
-Safely develop Data Science programs with a statically checked domain specific language (DSL).
+Safely develop Data Science programs with a statically checked domain specific language (DSL) and bundled data
+inspection tools.
+
+![demo](img/readme/demo.gif)
 
 ## Installation
 
@@ -17,10 +20,8 @@ Safely develop Data Science programs with a statically checked domain specific l
     1. Install [Python](https://www.python.org/) (3.11 or 3.12).
     2. Run `pip install "safe-ds-runner>=0.10.0,<0.11.0"` in a command line to download the latest matching Runner version
        from [PyPI](https://pypi.org/project/safe-ds-runner/).
-    3. If the Visual Studio Code extension cannot start the runner, adjust the setting `safe-ds.runner.command`.
-       Enter the absolute path to the Runner executable, as seen in the image below.
-
-        ![vscode-settings-safeds-runner-path.png](./img/vscode-settings-safeds-runner-path.png)
+   3. If the Visual Studio Code extension cannot start the runner, adjust the setting `safe-ds.runner.command`.
+      Enter the absolute path to the Runner executable.
 
 ## Documentation
 

packages/safe-ds-vscode/README.md

@@ -1,7 +1,31 @@
 # Safe-DS
 
-Safely develop Data Science programs with a statically checked domain specific language (DSL).
+Safely develop Data Science programs with a statically checked domain specific language (DSL) and bundled data
+inspection tools.
+
+![demo](https://github.com/Safe-DS/DSL/raw/main/docs/img/readme/demo.gif)
+
+## Installation
+
+1. Install this extension to set up a complete _development environment_ for Safe-DS programs.
+2. To _execute_ Safe-DS programs, the [Safe-DS Runner](https://github.com/Safe-DS/Runner) has to be installed and
+   configured additionally:
+    1. Install [Python](https://www.python.org/) (3.11 or 3.12).
+    2. Run `pip install "safe-ds-runner>=0.9.0,<0.10.0"` in a command line to download the latest matching Runner
+       version from [PyPI](https://pypi.org/project/safe-ds-runner/).
+    3. If the Visual Studio Code extension cannot start the runner, adjust the setting `safe-ds.runner.command`.
+       Enter the absolute path to the Runner executable.
 
 ## Documentation
 
 You can find the full documentation [here](https://dsl.safeds.com).
+
+## Contributing
+
+We welcome contributions from everyone. As a starting point, check the following resources:
+
+* [Contributing page](https://github.com/Safe-DS/DSL/contribute)
+
+If you need further help, please [use our discussion forum][forum].
+
+[forum]: https://github.com/orgs/Safe-DS/discussions