Docs: Move tupload_texts() example from guides to reference

[agnieszka-m]

Proposed Changes?

SOLs suggested upload_bytes() is the method we should promote in the guides, since they can use it for all file types, not just text. I'm deleting upload_texts() examples from https://docs.cloud.deepset.ai/docs/upload-files-with-python#upload-texts-or-bytes and moving them to reference. The how-tos will just have examples of upload_bytes.

How did you test it?

Notes for the reviewer

I'm not sure the formatting is OK.

Screenshots (optional)

Checklist

• [ ] I have updated the referenced issue with new insights and changes
• [ ] If this is a code change, I have added unit tests
• [ ] I've used the conventional commit specification for my PR title
• [ ] I updated the docstrings
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[github-actions[bot]]

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[sjrl]

Hey @agnieszka-m there were a few indenting changes I made, that were hard to create as suggestions, so I just made a quick commit!