CONTRIBUTING: Update with src -> chia renaming (Chia-Network#2721)

CONTRIBUTING.md

@@ -5,7 +5,7 @@ Welcome to the chia-blockchain project!
 We are happy that you are taking a look at the code for Chia, a proof of space and time cryptocurrency.
 
 A lot of fascinating new cryptography and blockchain concepts are used and implemented here.
-This repo includes the code for the Chia full node, farmer, and timelord (in src), which are all written in python.
+This repo includes the code for the Chia full node, farmer, and timelord (in chia folder), which are all written in python.
 It also includes a verifiable delay function implementation that it imports from the [chiavdf repo](https://github.com/Chia-Network/chiavdf) (in c/c++), and a proof of space implementation that it imports from the [chiapos repo](https://github.com/Chia-Network/chiapos). BLS signatures are imported from the [bls-signatures repo](https://github.com/Chia-Network/bls-signatures) as blspy. There is an additional dependency on the [chiabip158 repo](https://github.com/Chia-Network/chiabip158). For major platforms, binary and source wheels are shipped to PyPI from each dependent repo and then chia-blockchain can pip install those from PyPI or they can be prepackaged as is done for the Windows installer. On unsupported platforms, pip will fall back to the source distributions to be compiled locally.
 
 If you want to learn more about this project, read the [wiki](https://github.com/Chia-Network/chia-blockchain/wiki), or check out the [green paper](https://www.chia.net/assets/ChiaGreenPaper.pdf).
@@ -52,7 +52,7 @@ proofs of space during testing. The next time tests are run, this won't be neces
 ```bash
 . ./activate
 pip install ".[dev]"
-black src tests && mypy src tests && flake8 src tests
+black chia tests && mypy chia tests && flake8 chia tests
 py.test tests -v --durations 0
 ```
 
@@ -69,7 +69,7 @@ If you want verbose logging for tests, edit the tests/pytest.ini file.
 4. Preferences > Settings > Python > Linting > flake8 enabled
 5. Preferences > Settings > Python > Linting > mypy enabled
 6. Preferences > Settings > Formatting > Python > Provider > black
-7. Preferences > Settings > mypy > Targets: set to ./src and ./tests
+7. Preferences > Settings > mypy > Targets: set to ./chia and ./tests
 
 ## Configure Pycharm