Fix missing asset (#464)

## Problem

Commit 84aa1f7 moved the
`pinecone-python-client-fork.png` asset without updating
`CONTRIBUTING.md`.

## Solution

The PR updates `CONTRIBUTING.md` with the correct location of
`pinecone-python-client-fork.png`.

## 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)
- [ ] This change requires a documentation update
- [ ] Infrastructure change (CI configs, etc)
- [x] Non-code change (docs, etc)
- [ ] None of the above: (explain here)

## Test Plan

Signed-off-by: Emmanuel Ferdman <[email protected]>

Author: emmanuel-ferdman

CONTRIBUTING.md

@@ -35,7 +35,7 @@ The Pinecone Python client therefore supports Poetry as its primary means of ena
 
 On the [GitHub repository page](https://github.com/pinecone-io/pinecone-python-client) page, click the fork button at the top of the screen and create a personal fork of the repository:
 
-![Create a GitHub fork of the Pinecone Python client](./docs/pinecone-python-client-fork.png)
+![Create a GitHub fork of the Pinecone Python client](./pdoc/pinecone-python-client-fork.png)
 
 It will take a few seconds for your fork to be ready. When it's ready, **clone your fork** of the Pinecone python client repository to your machine.