Documentation misspells

[jmonticolo]

I was consulting the Plotly Python documentation and I ran into some misspells : dictioanry instead dictionary.

• 380,
• 500,
• 502.

[nicolaskruchten]

Thanks for letting us know! We'd be happy to accept a pull request to fix these :)

[jmonticolo]

I fixed this issue (with other misspells) but before PR, on which branch to PR for the v5 bump ?