[llvm] [libsycl] Add Maintainers.rst file (PR #168550)

[Kseniya Tikhomirova via llvm-commits]

================
@@ -511,6 +511,8 @@ Some subprojects maintain their own list of per-component maintainers.
 
 [libclc maintainers](https://github.com/llvm/llvm-project/blob/main/libclc/Maintainers.md)
 
+[libsycl maintainers](https://github.com/llvm/llvm-project/blob/main/libsycl/Maintainers.rst)
----------------
KseniyaTikhomirova wrote:

changed to md.

https://github.com/llvm/llvm-project/pull/168550