[docs] Initial code_owners.md

As discussed in #1506, this should help to distribute the review load
and ensure timely, high quality reviews.

Closes #1506

docs/code_owners.md

@@ -0,0 +1,54 @@
+This file is a list of the people responsible for ensuring that patches for a
+particular part of Torch-MLIR are reviewed, either by themself or by someone
+else. They are also the gatekeepers for their part of Torch-MLIR, with the final
+word on what goes in or not.
+
+This file follows the conventions of LLVM's
+[CODE_OWNERS.TXT](https://github.com/llvm/llvm-project/blob/main/llvm/CODE_OWNERS.TXT)
+and Clang's
+[CodeOwners.rst](https://github.com/llvm/llvm-project/blob/main/clang/CodeOwners.rst).
+
+--------------------------------------------------------------------------------
+
+### All parts not covered by anyone else
+
+- Sean Silva (@silvasean)
+- Stella Laurenzo (@stellaraccident) -- mostly emeritus
+
+--------------------------------------------------------------------------------
+
+### `torch` dialect and other core IR pieces, Python bindings/API, JIT IR importer
+
+- Sean Silva (@silvasean)
+
+### TorchToLinalg, Shape inference, Dtype refinement, MaximizeValueSemantics
+
+- Ramiro Leal-Cavazos (@ramiro050)
+
+### CI / Build system / Packaging
+
+- Anush Elangovan (@powderluv)
+
+### TorchToTOSA
+
+- Eric Kunze (@eric-k256)
+
+### TorchToMHLO
+
+- Tianyo Kwok (@tanyokwok)
+- Ziheng Jiang (@ZihengJiang)
+- Jiawei Wu (@Vremold)
+
+### LTC
+
+- Antonio Kim (@antoniojkim)
+- Ke Deng (@ke1337)
+
+### Bazel build
+
+- Sambhav Jain (@sjain-stanford)
+- Ahmed Taei (@asaadaldien)
+
+### LLVM Integrate
+
+- Ashay Rane (@ashay)