Add dev info

Author: eltos

.github/CONTRIBUTING.md

@@ -7,14 +7,24 @@ If you are new, check out the **[contribution page](https://github.com/eltos/Pas
 
 ## Developer setup
 
+Check the `TargetFrameworkVersion` in [PasteIntoFile.csproj](https://github.com/eltos/PasteIntoFile/blob/main/PasteIntoFile/PasteIntoFile.csproj)
+and then ownload and install the [.NET Framework developer pack](https://dotnet.microsoft.com/en-us/download/visual-studio-sdks#supported-versions-framework)
+for this version.
+
+
 This project uses [pre-commit](https://pre-commit.com) with [dotnet-format](https://github.com/dotnet/format) to ensure consistent file formatting and clean diffs.
 Please install these tools before committing:
 ```bash
 dotnet tool install --global dotnet-format --version 5.1.250801
 pip install pre-commit
 pre-commit install
+dotnet restore
 ```
 
+Other useful tools:
+- [InsideClipboard](https://www.nirsoft.net/utils/inside_clipboard.html) for analyzing clipboard structure
+- [JetBrains Rider](https://www.jetbrains.com/rider/) .NET IDE free for non-commercial use
+
 ## CI/CD
 This project uses GitHub actions for test builds, synchronisation with crowdin and releases.