More instructions to build CmdPal (#40644)

## Summary of the Pull Request

Added more instructions to first time building command palette

## PR Checklist

- [ ] **Closes:** #xxx
- [ ] **Communication:** I've discussed this with core contributors
already. If the work hasn't been agreed, this work might be rejected
- [ ] **Tests:** Added/updated and all pass
- [ ] **Localization:** All end-user-facing strings can be localized
- [X ] **Dev docs:** Added/updated
- [ ] **New binaries:** Added on the required places
- [ ] [JSON for
signing](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ESRPSigning_core.json)
for new binaries
- [ ] [WXS for
installer](https://github.com/microsoft/PowerToys/blob/main/installer/PowerToysSetup/Product.wxs)
for new binaries and localization folder
- [ ] [YML for CI
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ci/templates/build-powertoys-steps.yml)
for new test projects
- [ ] [YML for signed
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/release.yml)
- [ ] **Documentation updated:** If checked, please file a pull request
on [our docs
repo](https://github.com/MicrosoftDocs/windows-uwp/tree/docs/hub/powertoys)
and link it here: #xxx

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## Detailed Description of the Pull Request / Additional comments

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## Validation Steps Performed

src/modules/cmdpal/README.md

@@ -2,16 +2,15 @@
 
 Windows Command Palette ("CmdPal") is the next iteration of PowerToys Run. With extensibility at its core, the Command Palette is your one-stop launcher to start _anything_.
 
-By default, CmdPal is bound to <kbd>Win+Alt+Space</kbd>. 
-
+By default, CmdPal is bound to <kbd>Win+Alt+Space</kbd>.
 
 ## Creating an extension
 
-The fastest way to get started is just to run the "Create extension" command in the palette itself. That'll prompt you for a project name and a Display Name, and where you want to place your project. Then just open the `sln` it produces. You should be ready to go 🙂. 
+The fastest way to get started is just to run the "Create extension" command in the palette itself. That'll prompt you for a project name and a Display Name, and where you want to place your project. Then just open the `sln` it produces. You should be ready to go 🙂.
 
 The official API documentation can be found [on this docs site](https://learn.microsoft.com/windows/powertoys/command-palette/extensibility-overview).
 
-We've also got samples, so that you can see how the APIs in-action. 
+We've also got samples, so that you can see how the APIs in-action.
 
 * We've got [generic samples] in the repo
 * We've got [real samples] in the repo too
@@ -22,14 +21,22 @@ We've also got samples, so that you can see how the APIs in-action.
 
 ## Building CmdPal
 
-The Command Palette is included as a part of PowerToys. To get started building, open up the root `PowerToys.sln`, to get started building. 
+### Install & Build PowerToys
+
+1. Follow the install and build instructions for [PowerToys](https://github.com/microsoft/PowerToys/tree/main/doc/devdocs#compiling-powertoys)
+
+### Load & Build
+
+1. In Visual Studio, in the Solution Explorer Pane, confirm that all of the files/projects in `src\modules\CommandPalette` and `src\common\CalculatorEngineCommon` do not have `(unloaded)` on the right side
+    1. If any file has `(unloaded)`, right click on file and select `Reload Project`
+1. Now you can right click on one of the project below to `Build` and then `Deploy`:
 
 Projects of interest are:
 * `Microsoft.CmdPal.UI`: This is the main project for CmdPal. Build and run this to get the CmdPal.
 * `Microsoft.CommandPalette.Extensions`: This is the official extension interface. 
   * This is designed to be language-agnostic. Any programming language which supports implementing WinRT interfaces should be able to implement the WinRT interface. 
 * `Microsoft.CommandPalette.Extensions.Toolkit`: This is a C# helper library for creating extensions. This makes writing extensions easier.
-* Everything under "SampleExtensions": These are example plugins to demo how to author extensions. Deploy any number of these, to get a feel for how the extension API works. 
+* Everything under "SampleExtensions": These are example plugins to demo how to author extensions. Deploy any number of these, to get a feel for how the extension API works.
 
 ### Footnotes and other links