Merge pull request #1 from tqchen/docs-status

[DOCS] Add CI status badge

Author: cyx-6

README.md

@@ -16,3 +16,5 @@
 <!--- under the License. -->
 
 # tvm ffi
+
+[![CI](https://github.com/apache/tvm-ffi/actions/workflows/ci_test.yml/badge.svg)](https://github.com/apache/tvm-ffi/actions/workflows/ci_test.yml)