Update GoogleFonts functions documentation and required module versions

Author: MariusStorhaug

src/functions/public/Get-GoogleFont.ps1

@@ -20,6 +20,13 @@
         Get-GoogleFonts -Name 'Noto*'
 
         Get the GoogleFont with the name starting with 'Noto'.
+
+        .LINK
+        https://psmodule.io/GoogleFonts/Functions/Get-GoogleFont
+
+        .NOTES
+        More information about the GoogleFonts can be found at:
+        [GoogleFonts | GitHub](https://github.com/google/fonts)
     #>
     [Alias('Get-GoogleFonts')]
     [OutputType([System.Object[]])]

src/functions/public/Install-GoogleFont.ps1

@@ -1,4 +1,5 @@
-#Requires -Modules @{ ModuleName = 'Fonts'; RequiredVersion = '1.1.19' }
+#Requires -Modules @{ ModuleName = 'Fonts'; RequiredVersion = '1.1.21' }
+#Requires -Modules @{ ModuleName = 'Admin'; RequiredVersion = '1.1.6' }
 
 function Install-GoogleFont {
     <#
@@ -27,6 +28,13 @@ function Install-GoogleFont {
         Install-GoogleFont -All
 
         Installs all Google Fonts to the current user.
+
+        .LINK
+        https://psmodule.io/GoogleFonts/Functions/Install-GoogleFont
+
+        .NOTES
+        More information about the GoogleFonts can be found at:
+        [GoogleFonts | GitHub](https://github.com/google/fonts)
     #>
     [CmdletBinding(
         DefaultParameterSetName = 'ByName',