Add GitHub Actions workflows and funding file

This commit introduces a new folder structure within the solution to accommodate the GitHub Actions workflows and the funding file. The `.github` directory includes the `FUNDING.yml` for funding links and two workflow files, `dotnet.yml` and `dotnet-desktop.yml`, to automate various CI/CD tasks.

SubDBSharp.slnx

@@ -1,4 +1,11 @@
 <Solution>
+  <Folder Name="/.github/">
+    <File Path=".github\FUNDING.yml" />
+  </Folder>
+  <Folder Name="/.github/workflows/">
+    <File Path=".github\workflows\dotnet.yml" />
+    <File Path=".github\workflows\dotnet-desktop.yml" />
+  </Folder>
   <Folder Name="/.Solution Items/">
     <File Path="Directory.Packages.props" />
     <File Path="Directory.Build.props" />