[Docs] Add Docs on Limitations of VLM Support

[ywang96]

This PR adds an important note on the VLM page regarding current limitations on VLM support.

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[DarkLight1337]

You forgot a comma here. This might have messed up the docs

[ywang96]

Good catch (though I'm not sure about why the docs still build, both locally and remotely), will make a quick PR to fix