New: Add functionality to retrieve maintenance messages

coscine/issues#1296

.config/dotnet-tools.json

-{
-  "version": 1,
-  "isRoot": true,
-  "tools": {
-    "gitversion.tool": {
-      "version": "5.6.6",
-      "commands": [
-        "dotnet-gitversion"
-      ]
-    },
-    "dotnet-version-cli": {
-      "version": "2.1.1",
-      "commands": [
-        "dotnet-version"
-      ]
-    }
-  }
-}
\ No newline at end of file