Merge pull request #438 from filecoin-project/codeowners

chore: add experimental CODEOWNERS file

Author: porcuquine

CODEOWNERS

@@ -0,0 +1,8 @@
+# Global Owners
+* @porcuquine @dignifiedquire
+
+/storage-proofs/        @porcuquine @dignifiedquire
+/filecoin-proofs/       @porcuquine @dignifiedquire @laser
+/ffi-toolkit/           @laser
+/sector-base/           @porcuquine @laser
+/storage-backend/       @porcuquine @dignifiedquire