Update versions-manifest (#69)

Co-authored-by: Service account <no-reply@microsoft.com>

versions-manifest.json

@@ -1,4 +1,29 @@
 [
+  {
+    "version": "1.20.0",
+    "stable": true,
+    "release_url": "https://github.com/actions/go-versions/releases/tag/1.20.0-4072132786",
+    "files": [
+      {
+        "filename": "go-1.20.0-darwin-x64.tar.gz",
+        "arch": "x64",
+        "platform": "darwin",
+        "download_url": "https://github.com/actions/go-versions/releases/download/1.20.0-4072132786/go-1.20.0-darwin-x64.tar.gz"
+      },
+      {
+        "filename": "go-1.20.0-linux-x64.tar.gz",
+        "arch": "x64",
+        "platform": "linux",
+        "download_url": "https://github.com/actions/go-versions/releases/download/1.20.0-4072132786/go-1.20.0-linux-x64.tar.gz"
+      },
+      {
+        "filename": "go-1.20.0-win32-x64.zip",
+        "arch": "x64",
+        "platform": "win32",
+        "download_url": "https://github.com/actions/go-versions/releases/download/1.20.0-4072132786/go-1.20.0-win32-x64.zip"
+      }
+    ]
+  },
   {
     "version": "1.19.5",
     "stable": true,