Update README.md

[shenxianpeng]

• Add README.md and banner files

[shenxianpeng]

cpp-linter only provides integration with any CI environment, but also provides pre-commit hooks to check before committing.

There is a typo in the above sentence on the home page, it is missing "not". maybe changing to the following is better:

cpp-linter provides integration with any CI environment and pre-commit hooks to check before committing.

[2bndy5]

I understood it as it was, but that may be because I recognize the difference in the implementations. I think the way you re-word it is fine, but it might be better if we explicitly describe:

• cpp-linter as an organization.
• cpp-linter-action as a workflow step
• cpp-linter-hooks as a pre-commit workflow step