[Improvement]: There are 2 sets of examples in examples/

[XuanYang-cn]

Is there an existing issue for this?

• [X] I have searched the existing issues

Describe the bug

We need to tidy the examples/ directory.

The old_style APIs are not recommended, so they should be removed.

But the old_style APIs are carefully organized with plenty of comments, the orm-styled examples are somehow very rough, including the hello_milvus.py.

So here's what I suggest:

• Rewrite collection.py, connections.py, examples.py, example_index.py, hellow_milvus.py, and partition.py referring to the old_style_examples.
• Remove the old_style_examples.

Expected Behavior

No response

Steps/Code To Reproduce behavior

No response

Environment details

- Hardware/Softward conditions (OS, CPU, GPU, Memory):
- Method of installation (Docker, or from source):
- Milvus version (v0.3.1, or v0.4.0):
- Milvus configuration (Settings you made in `server_config.yaml`):

Anything else?

No response

[XuanYang-cn]

• [ ] #766
• [ ] #767
• [x] #768
• [x] #769
• [ ] #770
• [x] Rewrite hello_milvus.py

[sre-ci-robot]

@xiaohu4313888: GitHub didn't allow me to assign the following users: ZhiShen.

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In response to this:

/assign @ZhiShen

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[xiaohu4313888]

@XuanYang-cn, I want to work on this, can you assign me. Recently, I met some time-consuming things, I can't guarantee when I will solve this issue, maybe more than a month but no more than two months.

[XuanYang-cn]

@XuanYang-cn, I want to work on this, can you assign me. Recently, I met some time-consuming things, I can't guarantee when I will solve this issue, maybe more than a month but no more than two months.

@xiaohu4313888 Thanks, currently I found out that this is very hard, So I'm considering doing this issue by myself.