Fix typos discovered by codespell

[cclauss]

Fix typos discovered by codespell - https://pypi.org/project/codespell

% codespell README.md

README.md:217: Programing ==> Programming
README.md:316: entiy ==> entity
README.md:367: mesages ==> messages
README.md:1571: souce ==> source

% codespell README.md --write-changes

Description

[Briefly describe the changes made in this pull request.]

Related Issues

[Reference any related issues or tasks addressed by this pull request.]

Changes Made

[List the specific changes made in this pull request.]

Checklist

• Changes tested locally
• Code reviewed
• Documentation updated (if necessary)
• Unit tests added (if applicable)

Additional Notes

[Add any additional notes or context for the reviewer(s).]