fix(pwsh): correct encoding for config export

resolves #425

docs/docs/installation.mdx

@@ -339,14 +339,7 @@ available options first, by starting with the [configuration guide][configuratio
 You can output the current theme to its `JSON` representation which can be used to tweak and store as your custom theme.
 
 ```powershell
-Write-PoshTheme
-```
-
-Due to a bug in PowerShell, if you want to use `Out-File` directly to write the current theme to a new file, use the `oem`
-encoding to ensure the symbols are outputted correctly.
-
-```powershell
-Write-PoshTheme | Out-File -FilePath ~/.mytheme.omp.json -Encoding oem
+Export-PoshTheme -FilePath ~/.mytheme.omp.json
 ```
 
 Once you're done editing, adjust your `$PROFILE` to use your newly created theme.

docs/docs/upgrading.md

@@ -61,7 +61,7 @@ If you see one you like, set it, then export its config so you can customize/ext
 
 ```powershell
 Set-PoshPrompt -Theme jandedobbeleer
-Write-PoshTheme | Out-File -FilePath ~/.go-my-posh.json -Encoding oem
+Export-PoshTheme | Out-File -FilePath ~/.go-my-posh.json -Encoding oem
 ```
 
 Adjust the config (`~/.go-my-posh.json`) to your liking by going through the [configuration][configuration] guide.

packages/powershell/oh-my-posh/oh-my-posh.psd1

@@ -31,7 +31,7 @@
     # Aliases to export from this module
     AliasesToExport   = '*'
     # Functions to export from this module
-    FunctionsToExport = @('Get-PoshThemes', 'Set-PoshPrompt', 'Write-PoshTheme', 'Set-PoshContext', 'Get-PoshInfoForV2Users')
+    FunctionsToExport = @('Get-PoshThemes', 'Set-PoshPrompt', 'Export-PoshTheme', 'Set-PoshContext', 'Get-PoshInfoForV2Users')
     # Private data to pass to the module specified in RootModule. This may also contain a PSData hashtable with additional module metadata used by PowerShell.
     PrivateData       = @{
         PSData = @{

packages/powershell/oh-my-posh/oh-my-posh.psm1

@@ -92,10 +92,21 @@ function Get-PoshThemes {
     Write-Host ("=" * $consoleWidth)
 }
 
-function Write-PoshTheme {
+function Export-PoshTheme {
+    param(
+        [Parameter(Mandatory = $true)]
+        [string]
+        $FilePath
+    )
+
     $config = $global:PoshSettings.Theme
     $poshCommand = Get-PoshCommand
-    & $poshCommand -config $config -print-config
+    # Save current encoding and swap for UTF8
+    $originalOutputEncoding = [Console]::OutputEncoding
+    [Console]::OutputEncoding = [System.Text.Encoding]::UTF8
+    & $poshCommand -config $config -print-config | Out-File -FilePath $FilePath
+    # Restore initial encoding
+    [Console]::OutputEncoding = $originalOutputEncoding
 }
 
 # Helper function to create argument completion results