Add transaction page to docs (#70)

docs/index.rst

@@ -14,6 +14,7 @@
   datatypes
   exceptions
   api
+  transactions
 
 EdgeDB.Net is the official EdgeDB .NET client, compatable with C#, F# and
 VB.NET.

docs/transactions.rst

@@ -0,0 +1,61 @@
+.. _edgedb-dotnet-transactions:
+
+============
+Transactions
+============
+
+Transactions allow you to execute transactional code via the ``TransactionAsync`` API, retrying your 
+queries if a retryable error (e.g. a network failure) occurs. If an non-retryable error happens, 
+the queries performed within the transactions are automatically rolled back:
+
+.. tabs::
+
+  .. code-tab:: cs
+    :caption: C#
+
+    var client = new EdgeDBClient();
+
+    await client.TransactionAsync(async tx => 
+        await tx.ExecuteAsync("INSERT User { name := 'John Smith' }");
+    );
+
+  .. code-tab:: fsharp
+    :caption: F#
+
+    let client = new EdgeDBClient()
+
+    client.TransactionAsync(
+      fun tx -> tx.ExecuteAsync("INSERT User { name := 'John Smith' }")
+    ) |> Async.AwaitTask |> Async.Ignore |> ignore
+
+.. note::
+  Code blocks in transactions may run multiple times. It’s good practice to only perform safe to re-run operations in transaction blocks.
+
+The ``TransactionAsync`` method proxies the result of the transaction, allowing you to 
+get the result of a query executed in a transaction:
+
+.. tabs::
+
+  .. code-tab:: cs
+    :caption: C#
+
+    var client = new EdgeDBClient();
+
+    var transactionResult = await client.TransactionAsync(async tx => 
+        await tx.QueryRequiredSingleAsync<string>("SELECT 'Hello from Transaction!'");
+    );
+
+    Console.WriteLine(transactionResult);
+
+  .. code-tab:: fsharp
+    :caption: F#
+
+    let client = new EdgeDBClient()
+
+    client.TransactionAsync(
+      fun tx -> tx.QueryRequiredSingleAsync<string>("SELECT 'Hello from Transaction!'")
+    )
+    |> Async.AwaitTask
+    |> Async.RunSynchronously
+    |> fun r -> printfn "Transaction result: %s" r
+