Add note about using cargo with private dependencies (#64)

* Add note about using cargo with private dependencies

* Update doc to mention Windows only

* Add alternative workaround

* Create extra main section for tips and information regarding different languages/tools

Co-authored-by: Matthias Pigulla <mp@webfactory.de>

README.md

@@ -90,6 +90,38 @@ If the private key is not in the `PEM` format, you will see an `Error loading ke
 
 Use `ssh-keygen -p -f path/to/your/key -m pem` to convert your key file to `PEM`, but be sure to make a backup of the file first 😉.
 
+## Additional Information for Particular Tools or Platforms
+
+If you know that your favorite tool or platform of choice requires extra tweaks or has some caveats when running with SSH, feel free to open a PR to amend this section here.
+
+### Cargo's (Rust) Private Dependencies on Windows
+
+If you are using private repositories in your dependencies like this:
+
+```
+stuff = { git = "ssh://git@github.com/myorg/stuff.git", branch = "main" }
+```
+
+... you will need to change a configuration in the workflow for Windows machines in order to make cargo able to clone private repositories.
+
+There are 2 ways you can achieve this:
+
+1. Add this step once in your job **before** any cargo command:
+
+```
+      - name: Update cargo config to use Git CLI
+        run: Set-Content -Path $env:USERPROFILE\.cargo\config.toml "[net]`ngit-fetch-with-cli = true"
+```
+
+This will configure Cargo to use the Git CLI as explained in the [Cargo's documentation](https://doc.rust-lang.org/cargo/reference/config.html#netgit-fetch-with-cli).
+
+2. Alternatively you can set it to the environment variables for the entire workflow:
+
+```
+env:
+  CARGO_NET_GIT_FETCH_WITH_CLI: true
+```
+
 ## What this Action *cannot* do for you
 
 The following items are not issues, but beyond what this Action is supposed to do.