Update readme to include OSS references (#5433)

Summary:
Pull Request resolved: #5433

^

Reviewed By: dvorjackz

Differential Revision: D62887806

fbshipit-source-id: 756b0ba47873fa861e67ea992ec3f9998ebcfd69

Author: lucylq

extension/module/test/resources/README.md

@@ -1,4 +1,11 @@
 ## Resources
 
 ### model.pte
-- generated via `buck2 run fbcode//executorch/examples/portable/scripts:export -- --model_name="add"` after D62209852.
+- Internally generated after D62209852, 2024-09-06 with:
+    ```
+    buck2 run fbcode//executorch/examples/portable/scripts:export -- --model_name="add"
+    ```
+- In OSS, the same file can be generated after [#5145](https://github.com/pytorch/executorch/pull/5145), 2024-09-06 with:
+    ```
+    python -m examples.portable.scripts.export --model_name="add"
+    ```

test/models/deprecated/README.md

@@ -3,7 +3,7 @@
 This readme documents deprecated models that remain compatible with versions of the ExecuTorch runtime.
 
 ModuleLinear-no-constant-segment.pte
-- This file contains constants stored in the constant_buffer, which was deprecated in D61996249 on 2024-09-05. Now, constants are stored in a separate segment.
+- This file contains constants stored in the constant_buffer, which was deprecated in D61996249, [#5096](https://github.com/pytorch/executorch/pull/5096) on 2024-09-06. Now, constants are stored in a separate segment.
 - This .pte file was generated internally using hg commit hash rFBS5e49dc0319b1d2d9969bbcef92857ab76a899c34, with command:
     ```
     buck2 build fbcode//executorch/test/models:exported_programs[ModuleLinear-no-constant-segment.pte] --show-output