docs: create-app troubleshooting and python requirement

docs/getting-started/create-an-app.md

@@ -38,6 +38,34 @@ app-folder is the name that was provided when prompted.
 Inside that directory, it will generate all the files and folder structure
 needed for you to run your app.
 
+### Troubleshooting
+
+The create app command doesn't always work as expected, this is a collection of
+some of the commonly encountered issues and solutions.
+
+#### Couldn't find any versions for "file-saver"
+
+You may encounter the following error message:
+
+```text
+Couldn't find any versions for "file-saver" that matches "eligrey-FileSaver.js-1.3.8.tar.gz-art-external"
+```
+
+This is likely because you have a globally configured NPM proxy, which breaks
+the installation of the `material-table` dependency. This is a known issue and
+being worked on in `material-table`, but for now you can work around it using
+the following:
+
+```bash
+NPM_CONFIG_REGISTRY=https://registry.npmjs.org npx @backstage/create-app
+```
+
+#### Can't find Python executable "python"
+
+The install process may also fail if no Python installation is available. Python
+is commonly available in most systems already, but if it isn't you can head for
+example [here](https://www.python.org/downloads/) to install it.
+
 ### General folder structure
 
 Below is a simplified layout of the files and folders generated when creating an

docs/getting-started/index.md

@@ -24,9 +24,11 @@ Requests towards this repo.
 Backstage provides the `@backstage/create-app` package to scaffold standalone
 instances of Backstage. You will need to have
 [NodeJS](https://nodejs.org/en/download/) Active LTS Release installed
-(currently v12), and [yarn](https://classic.yarnpkg.com/en/docs/install). You
-will also need to have [Docker](https://docs.docker.com/engine/install/)
-installed to use some features like Software Templates and TechDocs.
+(currently v12), [yarn](https://classic.yarnpkg.com/en/docs/install) and
+[Python](https://www.python.org/downloads/) (although you likely have it
+already). You will also need to have
+[Docker](https://docs.docker.com/engine/install/) installed to use some features
+like Software Templates and TechDocs.
 
 Using `npx` you can then run the following to create an app in a chosen
 subdirectory of your current working directory:

docs/tutorials/quickstart-app-auth.md

@@ -11,10 +11,11 @@ title: Monorepo App Setup With Authentication
 > own environment. It starts with a skeleton install and verifying of the
 > monorepo's functionality. Next, GitHub authentication is added and tested.
 >
-> This document assumes you have NodeJS 12 active along with Yarn. Please note,
-> that at the time of this writing, the current version is 0.1.1-alpha.21. This
-> guide can still be used with future versions, just, verify as you go. If you
-> run into issues, you can compare your setup with mine here >
+> This document assumes you have NodeJS 12 active along with Yarn and Python.
+> Please note, that at the time of this writing, the current version is
+> 0.1.1-alpha.21. This guide can still be used with future versions, just,
+> verify as you go. If you run into issues, you can compare your setup with mine
+> here >
 > [simple-backstage-app](https://github.com/johnson-jesse/simple-backstage-app).
 
 # The Skeleton Application

docs/tutorials/quickstart-app-plugin.md

@@ -20,10 +20,11 @@ title: Adding Custom Plugin to Existing Monorepo App
 > functionality, extend the Sidebar to make our life easy. Finally, we add
 > custom code to display GitHub repository information.
 >
-> This document assumes you have NodeJS 12 active along with Yarn. Please note,
-> that at the time of this writing, the current version is 0.1.1-alpha.21. This
-> guide can still be used with future versions, just, verify as you go. If you
-> run into issues, you can compare your setup with mine here >
+> This document assumes you have NodeJS 12 active along with Yarn and Python.
+> Please note, that at the time of this writing, the current version is
+> 0.1.1-alpha.21. This guide can still be used with future versions, just,
+> verify as you go. If you run into issues, you can compare your setup with mine
+> here >
 > [simple-backstage-app-plugin](https://github.com/johnson-jesse/simple-backstage-app-plugin).
 
 # The Skeleton Plugin