C# bindings (#650)

* First workin version of the C# bindings

* Update README.md

Signed-off-by: mvenditto <venditto.matteo@gmail.com>

* Added more docs + fixed prompt callback signature

* build scripts revision

* Added .editorconfig + fixed style issues

---------

Signed-off-by: mvenditto <venditto.matteo@gmail.com>

gpt4all-bindings/csharp/Gpt4All/Extensions/PredictRequestOptionsExtensions.cs

@@ -0,0 +1,25 @@
+using Gpt4All.Bindings;
+
+namespace Gpt4All.Extensions;
+
+public static class PredictRequestOptionsExtensions
+{
+    public static LLModelPromptContext ToPromptContext(this PredictRequestOptions opts)
+    {
+        return new LLModelPromptContext
+        {
+            LogitsSize = opts.LogitsSize,
+            TokensSize = opts.TokensSize,
+            TopK = opts.TopK,
+            TopP = opts.TopP,
+            PastNum = opts.PastConversationTokensNum,
+            RepeatPenalty = opts.RepeatPenalty,
+            Temperature = opts.Temperature,
+            RepeatLastN = opts.RepeatLastN,
+            Batches = opts.Batches,
+            ContextErase = opts.ContextErase,
+            ContextSize = opts.ContextSize,
+            TokensToPredict = opts.TokensToPredict
+        };
+    }
+}