🩹 [Patch]: Add condition to add data loader on root module (#24)

## Description

- Only add data loader if a data folder exists.

## Type of change

<!-- Use the check-boxes [x] on the options that are relevant. -->

- [ ] 📖 [Docs]
- [ ] 🪲 [Fix]
- [x] 🩹 [Patch]
- [ ] ⚠️ [Security fix]
- [ ] 🚀 [Feature]
- [ ] 🌟 [Breaking change]

## Checklist

<!-- Use the check-boxes [x] on the options that are relevant. -->

- [x] I have performed a self-review of my own code
- [x] I have commented my code, particularly in hard-to-understand areas

Author: MariusStorhaug

README.md

@@ -37,7 +37,7 @@ The root module file is the main file that is loaded when the module is imported
 It is built from the source code files in the module folder in the following order:
 
 1. Adds module headers from `header.ps1`.
-1. Adds data loader automation that loads files from the `data` folder as variables in the module scope. The variables are available using the ´$script:<filename>´ syntax.
+1. Adds data loader automation that loads files from the `data` folder as variables in the module scope, if it exists. The variables are available using the ´$script:<filename>´ syntax.
 1. Adds content from subfolders, in the order:
    - Init
    - Private

scripts/helpers/Build/Build-PSModuleRootModule.ps1

@@ -74,7 +74,9 @@ Write-Verbose "[$scriptName] Importing module"
     #endregion - Module post-header
 
     #region - Data and variables
-    Add-Content -Path $rootModuleFile.FullName -Force -Value @'
+    if (Test-Path -Path (Join-Path -Path $ModuleOutputFolder -ChildPath 'data')) {
+
+        Add-Content -Path $rootModuleFile.FullName -Force -Value @'
 #region - Data import
 Write-Verbose "[$scriptName] - [data] - Processing folder"
 $dataFolder = (Join-Path $PSScriptRoot 'data')
@@ -89,6 +91,7 @@ Write-Verbose "[$scriptName] - [data] - Done"
 #endregion - Data import
 
 '@
+    }
     #endregion - Data and variables
 
     #region - Add content from subfolders