added Stargazers Over Time Chart at the bottom and fixed the image URLs to use the OWASP repo

Checklist

• I have followed the Contributor Guidelines.
• The code has been thoroughly tested in my local development environment with flake8 and pylint.
• The code is Python 3 compatible.
• The code follows the PEP8 styling guidelines with 4 spaces indentation.
• This Pull Request relates to only one issue or only one feature
• I have referenced the corresponding issue number in my commit message
• I have added the relevant documentation.
• My branch is up-to-date with the Upstream master branch.

Changes proposed in this pull request

added Stargazers Over Time Chart at the bottom and fixed the image URLs to use the OWASP repo

Your development environment

• OS: MacOS
• OS Version: 10.16
• Python Version: 3.11