Provide installation examples that work from command prompt as well as PowerShell

When installing ChocolateyGui and passing package parameters on install as per the example on [the package page](https://chocolatey.org/packages/ChocolateyGUI), the parameters are not actually set for the package.

**CLI used**: `cmd` / run as admin
**Choco**: 0.10.15
**ChocolateyGUI**: 0.17.20

Command passed:
```
choco install chocolateygui --package-parameters="'/ShowConsoleOutput=$true /ShowAdditionalPackageInformation=$true'"
```

When opening the GUI once the command has finished and going to `settings`, the settings which were passed on the command-line on install have not been set.

Output log: https://gist.github.com/jrfnl/454a553a667b8510c2ee677e07f5f195

[Line 776-777](https://gist.github.com/jrfnl/454a553a667b8510c2ee677e07f5f195#file-chocolateygui-log-L776-L777) show that the parameters _are_ picked up correctly.

The actual problem is most likely related to the logs on [lines 782-783](https://gist.github.com/jrfnl/454a553a667b8510c2ee677e07f5f195#file-chocolateygui-log-L782-L783):
```
2021-01-09 11:41:19,555 2308 [DEBUG] - Elevating permissions and running ["chocolateyguicli" feature disable --name=ShowConsoleOutput]. This may take a while, depending on the statements.
2021-01-09 11:41:19,555 2308 [WARN ] - WARNING: May not be able to find 'chocolateyguicli'. Please use full path for executables.
```

Start with the installation example on the linked ChocolateyGUI package page and compare its command-prompt and PowerShell syntax with the reported command. Update the examples so package parameters are passed correctly in both shells, then verify that the settings are applied after installation.

Written by the indexing model from the issue text.