(doc) Updates Contributing.md with Changes

Author: JPRuskin

CONTRIBUTING.md

@@ -2,35 +2,62 @@ This document outlines how to help with development of the Chocolatey Quickstart
 
 ## Development
 
-When looking to make a change ensure any working branch is taken from `develop`. You can do this with the following:
+When looking to make a change ensure any working branch is taken from the tip of `main`. You can do this with the following:
 
 ```powershell
-git checkout develop
-git fetch upstream
-git rebase upstream/develop
-git push origin
-git checkout -b $NewBranchName
+$ChocolateyUpstream = ((git remote -v) -match "github.com/chocolatey/choco-quickstart-scripts.git \(fetch\)$" -split "\t")[0]
+git fetch $ChocolateyUpstream
+git checkout -b $NewBranchName $ChocolateyUpstream/main
 ```
 
-## Testing
+### Development Testing
 
-Test your changes before raising a Pull Request to merge your changes. In order to set things up for testing do the following:
+You must test your changes before submitting a PR.
 
-1. Set `$env:CHOCO_QSG_DEVELOP = $true`
-1. The first step of the Guide will need amended to fetch from the `develop` branch:
+You should test on a clean, supported operating system.
+
+> NB: To save time in repeated testing from a clean environment, you can run the OfflineInstallPreparation script in your repository and copy the files directory before copying.
+
+To test the quickstart environment:
+
+1. Copy the repository directory over to `C:\choco-setup\files\` on the test machine. You do not need to copy the `.git` directory.
+1. Open an elevated Windows PowerShell console.
+1. Run `C:\choco-setup\files\Start-C4bSetup.ps1`, and continue through the guide steps as detailed in `README.md`.
+1. Run `C:\choco-setup\files\Start-C4bVerification.ps1` and check that all tests pass.
+
+## Testing a PR
+
+Changes in a PR must be tested before merging. In order to set things up for testing do the following in an elevated Windows PowerShell terminal:
+
+1. Set `$env:CHOCO_QSG_BRANCH` to the PR ID or Branch Name to download.
+1. Run Quickstart Guide as documented, in the same session.
+
+Example:
 
 ```powershell
+$env:CHOCO_QSG_BRANCH = "< Insert PR ID or Upstream BranchName Here >"
+
 Set-ExecutionPolicy Bypass -Scope Process -Force
 [Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::tls12
-$QuickStart = 'https://raw.githubusercontent.com/chocolatey/choco-quickstart-scripts/develop/Start-C4bSetup.ps1'
-$Script = [System.Net.Webclient]::new().DownloadString($QuickStart)
-$sb = [ScriptBlock]::Create($Script)
-& $sb
+Invoke-RestMethod "https://ch0.co/qsg-go" | Invoke-Expression
 ```
 
 1. Perform each step of the Quickstart Guide, and make sure the changes you have attempted to make work appropriately.
+1. Run `Start-C4bVerification.ps1` and check that all tests pass.
 1. If everything looks OK, push your branch and create your Pull Request.
 
-## SSL Certificates for testing
+## Creating a PR
+
+Push your branch to a fork or repository, and create a new PR [here](https://github.com/chocolatey/choco-quickstart-scripts/compare).
+
+You should fill out the issue template as much as possible.
 
-Reach out to Stephen, and he can generate a Let's Encrypt certificate for you.
+### Rebasing Your Branch
+
+If something else has been merged since you created your branch, you should rebase your branch onto the new tip of `main`. If you'd already pushed the branch, you may need to force-push the new history over the upstream version. You can do this as follows:
+
+```powershell
+$ChocolateyUpstream = ((git remote -v) -match "github.com/chocolatey/choco-quickstart-scripts.git \(fetch\)$" -split "\t")[0]
+git fetch $ChocolateyUpstream
+git rebase $ChocolateyUpstream\main --autostash
+```