Update gitignore with 'bin/'

[osamahan999]

No description provided.

[jzacsh]

what is bin/? is something in our project generating files in that directory?

[osamahan999]

@jzacsh Using intellij or VSCode generates bin/ files for the compiled java code.

[osamahan999]

Or maybe its something that is happening locally for me if no one else ran into it?

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