Bump markdown from 3.2.1 to 3.8.1 in /res/TensorFlowPythonModels

Bumps [markdown](https://github.com/Python-Markdown/markdown) from 3.2.1 to 3.8.1.
- [Release notes](https://github.com/Python-Markdown/markdown/releases)
- [Changelog](https://github.com/Python-Markdown/markdown/blob/master/docs/changelog.md)
- [Commits](Python-Markdown/markdown@3.2.1...3.8.1)

---
updated-dependencies:
- dependency-name: markdown
  dependency-version: 3.8.1
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

res/TensorFlowPythonModels/requirements.txt

@@ -5,7 +5,7 @@ grpcio==1.27.2
 h5py==2.10.0
 Keras-Applications==1.0.8
 Keras-Preprocessing==1.1.0
-Markdown==3.2.1
+Markdown==3.8.1
 mock==4.0.2
 numpy==1.18.2
 pkg-resources==0.0.0