UX: updating to a newer version of Fantomas

In #836, we introduced a whole new brave world of choosing your own Fantomas version.
These last weeks, we've published [two new versions of Fantomas](https://www.nuget.org/packages/fantomas-tool/4.6.0-alpha-006) that are also compatible with Ionide.

The question remains, how do we want to inform the user of these updates?
We can easily detect new versions via the NuGet API:
```fsharp
#r "nuget: NuGet.Protocol"

open System
open System.Threading
open NuGet.Common
open NuGet.Versioning
open NuGet.Protocol
open NuGet.Protocol.Core.Types

type SemanticVersion with

member this.Alpha: int option =
if isNull this.Release then
None
else
this.Release.Replace("alpha-", "")
|> Int32.TryParse
|> fun (success, alpha) -> if success then Some alpha else None

async {
let logger = NullLogger.Instance
let cancellationToken = CancellationToken.None

let cache = new SourceCacheContext()

let repository =
Repository.Factory.GetCoreV3("https://api.nuget.org/v3/index.json")

let! resource =
repository.GetResourceAsync()
|> Async.AwaitTask

let! versions =
resource.GetAllVersionsAsync(
"fantomas-tool",
cache,
logger,

cancellationToken
)
|> Async.AwaitTask

versions
|> Seq.filter (fun v ->
v.Major = 4
&& v.Minor = 6
&& (Option.map (fun alpha -> alpha >= 4) v.Alpha
|> Option.defaultValue true)
)
|> Seq.iter (fun v -> printfn "%A" v.Release)
}
|> Async.RunSynchronously

```

But how do we want to deal with this?
Some people will be interested in every version (alpha, beta, stable), while others will only care for revisions or minors.