[Feature] Add "alias" for "pwsh", short for "powershell"

[o-l-a-v]

Is your feature request related to a problem? Please describe.

Some other code in markdown highlighters, like GitHub itself, support defining pwsh as well as powershell for PowerShell.

Current behavior:

Would be nice if this Obsidian extension could add support for this too.

I don't know if it can be added to this extension, or if it should be raised upstream with either Shiki or Obsidian.

Describe the solution you'd like

This:

```pwsh
Write-Output -InputObject 'Hello'
```

Should be highlighted as PowerShell too.

Additional context
Add any other context or screenshots about the feature request here.

[mProjectsCode]

I am hesitant to add new aliases beyond what Shiki supplies.

[NobbZ]

@mProjectsCode I can understand this. And it feels weird that shiki doesn't provide common aliases on its own.

Like I am considering PR-ing shiki to provide some aliases for Elixir (ex, exs) as I miss them in your plugin.

Now I am wondering, can you provide config to add aliases per vault? That would be a good compromise and allow us to do whatever is necessary, without having to wait for shiki to accept a PR, and you syncing the shiki version.