Initial Setup, Step 4, increased clarity on version

It is not clear until chapter 3 that the remainder of the tutorial will assume we chose a pruned testnet. When I first did the setup I used a pruned mainnet, and thus by chapter 3 I had to rebuild the node so that I could better follow along. In retrospect it might seem apparent from the warning about using real funds in earlier paragraphs, but to reduce any confusion it should be elucidated here.

Author: icculp

02_1_Setting_Up_a_Bitcoin-Core_VPS_with_StackScript.md

@@ -50,7 +50,7 @@ You're now ready to create a node based on the Stackscript.
    * **Fully Qualified Hostname.** If you're going to include this VPS as part of a network with full DNS records, type in the hostname with its domain. For example, "mybtctest.mydomain.com". Otherwise, just repeat the short hostname and add ".local", for example "mybtctest.local".
 3. Enter the password for the "standup" user.
 4. Choose an Installation Type in the advanced options. 
-   * **Installation Type.** This is likely "Mainnet" or "Pruned Mainnet" if you are setting up a node for usage and "Testnet" or "Pruned Testnet" if you're just playing around. See the [Synopsis](#synopsis-bitcoin-installation-types) for more information on these options. (Note that if you plan to try out the Lightning chapters, you'll probably want to use an Unpruned node, as working with Pruned nodes on Lightning is iffy. See [§18.1](18_1_Verifying_Your_Lightning_Setup.md#compiling-the-source-code) for the specifics.)
+   * **Installation Type.** This is likely "Mainnet" or "Pruned Mainnet" if you are setting up a node for usage and "Testnet" or "Pruned Testnet" if you're just playing around. The bulk of this tutorial will assume you chose "Pruned Testnet", but you should still be able to follow along with other types. See the [Synopsis](#synopsis-bitcoin-installation-types) for more information on these options. (Note that if you plan to try out the Lightning chapters, you'll probably want to use an Unpruned node, as working with Pruned nodes on Lightning is iffy. See [§18.1](18_1_Verifying_Your_Lightning_Setup.md#compiling-the-source-code) for the specifics.)
 5. Fill in any other appropriate advanced options.
    * **X25519 Public Key.** This is a public key to add to Tor's list of authorized clients. If you don't use it, anyone who gets the QR code for your node can access it. You'll get this public key from whichever client you're using to connect to your node. For example, if you use [FullyNoded 2](https://github.com/BlockchainCommons/FullyNoded-2), you can go to its settings and "Export Tor V3 Authentication Public Key" for use here.
   * **SSH Key.** Copy your local computer's SSH key here; this allows you be able to automatically login in via SSH to the standup account. If you haven't setup an SSH key on your local computer yet, there are good instructions for it on [Github](https://help.github.com/articles/generating-a-new-ssh-key-and-adding-it-to-the-ssh-agent/).  You may also want to add your SSH key into your Linode LISH (Linode Interactive Shell) by going to your "Linode Home Page / My Preferences / LISH Settings /  LISH Keys". Using an SSH key will give you a simpler and safer way to log in to your server.