Migrate to the new solution format

Author: TolikPylypchuk

.github/workflows/main.yml

@@ -33,7 +33,7 @@ jobs:
       - name: Test Matchmaker
         shell: pwsh
         run: |
-          dotnet test Matchmaker.sln --nologo -c Release /p:ContinuousIntegrationBuild=true
+          dotnet test Matchmaker.slnx --nologo -c Release /p:ContinuousIntegrationBuild=true
 
       - name: Pack Matchmaker
         shell: pwsh

Matchmaker.sln

@@ -0,0 +1,37 @@
+<Solution>
+  <Folder Name="/Solution Items/">
+    <File Path=".editorconfig" />
+    <File Path=".gitattributes" />
+    <File Path=".github/workflows/main.yml" />
+    <File Path=".gitignore" />
+    <File Path="CHANGELOG.md" />
+    <File Path="LICENSE" />
+    <File Path="README.md" />
+  </Folder>
+  <Folder Name="/Solution Items/docs/">
+    <File Path="docs/.gitignore" />
+    <File Path="docs/docfx.json" />
+    <File Path="docs/favicon.ico" />
+    <File Path="docs/index.md" />
+    <File Path="docs/logo.svg" />
+    <File Path="docs/toc.yml" />
+  </Folder>
+  <Folder Name="/Solution Items/docs/api/">
+    <File Path="docs/api/.gitignore" />
+    <File Path="docs/api/index.md" />
+  </Folder>
+  <Folder Name="/Solution Items/docs/articles/">
+    <File Path="docs/articles/async.md" />
+    <File Path="docs/articles/expressions.md" />
+    <File Path="docs/articles/intro.md" />
+    <File Path="docs/articles/migration.md" />
+    <File Path="docs/articles/nullable.md" />
+    <File Path="docs/articles/patterns.md" />
+    <File Path="docs/articles/results.md" />
+    <File Path="docs/articles/toc.yml" />
+    <File Path="docs/articles/unions.md" />
+    <File Path="docs/articles/why.md" />
+  </Folder>
+  <Project Path="Matchmaker.Tests/Matchmaker.Tests.csproj" />
+  <Project Path="Matchmaker/Matchmaker.csproj" />
+</Solution>