create an examples folder to demonstrate various usage

[2bndy5]

It would be a good idea to have an examples folder (with a README in it) that demonstrates how to use commonly desirable configurations.

Example ideas include:

• run clang-tidy only
• run clang-format only
• apply thread-comments to only pull requests in workflows that also trigger on push events (similar to example in root README)
• how to commit changes if checks fail (without using PR review suggestions) cpp-linter#82

Originally posted by @2bndy5 in #193 (comment)

[shenxianpeng]

So we will have two folders? One is demo and another is examples? How about move folder demo to examples

[2bndy5]

Yeah, we could do that.