Add .LINK sections to public function documentation (#12)

## Summary

This PR adds `.LINK` sections to the comment-based help for public
functions, pointing to the repository's GitHub Pages documentation.

## Changes

- **Get-Greeting.ps1**: Added `.LINK` section pointing to
`https://MariusStorhaug.github.io/MariusTestModule/Functions/Get-Greeting/`
- **Get-PSModuleTest.ps1**: Added `.LINK` section pointing to
`https://MariusStorhaug.github.io/MariusTestModule/Functions/Get-PSModuleTest/`

## Benefits

- Users can easily access online documentation via `Get-Help
<FunctionName>` output
- Provides a direct reference to comprehensive documentation on GitHub
Pages

Author: MariusStorhaug

.github/workflows/Process-PSModule.yml

@@ -30,3 +30,4 @@ jobs:
     uses: PSModule/Process-PSModule/.github/workflows/workflow.yml@releasenotes
     secrets:
       APIKey: ${{ secrets.APIKey }}
+

src/functions/public/Get-Greeting.ps1

@@ -10,6 +10,9 @@
         Get-Greeting -TimeOfDay 'Morning'
 
         Returns "Good Morning!"
+
+        .LINK
+        https://MariusStorhaug.github.io/MariusTestModule/Functions/Get-Greeting/
     #>
     [OutputType([string])]
     [CmdletBinding()]

src/functions/public/Get-PSModuleTest.ps1

@@ -12,6 +12,9 @@
         ```
 
         "Hello, World!"
+
+        .LINK
+        https://MariusStorhaug.github.io/MariusTestModule/Functions/Get-PSModuleTest/
     #>
     [CmdletBinding()]
     param (