Auto Labeler Setup, Just C# for now (#6218)

* Auto Labeler Setup, Just C# for now

* Removed trailer comma as that might caused the issue

* Removed any[].

* Changed .cs glob

.github/labeler.yml

@@ -0,0 +1,13 @@
+# Configuration for Auto Labeler during pull request
+#
+# See https://github.com/actions/labeler for file format
+# and https://github.com/google/flatbuffers/labels for a list of valid labels
+#
+# See .github/workflows/label.yml for Github Action workflow script
+
+c#:
+  - ./**/*.cs 
+  - net/**/*
+  - tests/FlatBuffers.Test/**/*
+  - tests/FlatBuffers.Benchmarks/**/*
+  - src/idl_gen_csharp.cpp

.github/workflows/label.yml

@@ -0,0 +1,19 @@
+# This workflow will triage pull requests and apply a label based on the
+# paths that are modified in the pull request.
+#
+# To use this workflow, you will need to set up a .github/labeler.yml
+# file with configuration.  For more information, see:
+# https://github.com/actions/labeler
+
+name: Labeler
+on: [pull_request]
+
+jobs:
+  label:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/labeler@v2
+      with:
+        repo-token: "${{ secrets.GITHUB_TOKEN }}"