Rename package from pinecone-client to pinecone

[jhamon]

Problem

We want to rename this package from pinecone-client to pinecone.

Solution

• Update pyproject.toml to refer to the new name pinecone
• Find and replace references to old package name in README and docstrings
• Remove nightly publish job that would need to be updated but has been broken for a long time for other reasons

After this rename, we will need to setup a separate project to wrap this and continue publishing it under the old pinecone-client name for people who may not know about the rename, very similar to how old releases have been republished as pinecone using this wrapper project.

Type of Change

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [x] This change requires a documentation update
• [ ] Infrastructure change (CI configs, etc)
• [ ] Non-code change (docs, etc)
• [x] None of the above: We plan to publish a wrapper package under the name pinecone-client. So this shouldn't be a breaking change for end users consuming updates via the old name.

Test Plan

Describe specific steps for validating this change.

[jhamon]

What's the reason for renaming the package?

We went through a long process this year to get control of the package name pinecone which was previously being squatted by an inactive project. Pinecone is our trademark, so makes sense that we should have the name since it wasn't really being used. Now we have to do some work to migrate over everything (docs, etc) but don't want to break compatibility with anything else out there referencing the old name.