Explicitly install all dependencies in GS guide (#384)

* Explicitly install all dependencies in GS guide

Spago 0.20.0 requires that direct dependencies are explicitly installed. Previously, `foldable-traversable` was installed via `lists` as a transitive dependency.

Fixes #383

* Update guides/Getting-Started.md

Co-authored-by: Mohammed Anas <6daf084a-8eaf-40fb-86c7-8500077c3b69@anonaddy.me>

Co-authored-by: Thomas Honeyman <admin@thomashoneyman.com>
Co-authored-by: Mohammed Anas <6daf084a-8eaf-40fb-86c7-8500077c3b69@anonaddy.me>

Author: 3 people

guides/Getting-Started.md

@@ -58,11 +58,11 @@ If everything was built successfully, and the tests ran without problems, then t
 
 ### Installing Dependencies
 
-Dependencies can be installed using Spago. We will be using the `lists` library shortly, so install it now:
+Dependencies can be installed using Spago. We will be using the `lists` and `foldable-traversable` libraries shortly, so install those now:
 
-    spago install lists
+    spago install lists foldable-traversable
 
-The `lists` library sources should now be available in the `.spago/lists/{version}/` subdirectory, and will be included when you compile your project.
+The `lists` and `foldable-traversable` library sources should now be available in the `.spago/lists/{version}/` and `.spago/foldable-traversable/{version}/` subdirectories respectively, and will be included when you compile your project.
 
 ### Working in PSCI