chore: simplify contributing to match previous self promotion changes

Relates to #4780

Signed-off-by: jmeridth <jmeridth@gmail.com>

Author: jmeridth

CONTRIBUTING.md

@@ -98,7 +98,7 @@ To propose a new topic or collection, please **open a pull request** with your p
 
 ## Guidelines
 
-- Avoid conflicts of interest. These should be of general community interest, not a marketing vehicle for a product or a personal project. If you are a direct employee of a company creating the project, or the creator and sole maintainer, it's unlikely to be accepted.
+- Avoid conflicts of interest. These should be of general community interest, not self promotion. If it is self promotion, it's unlikely to be accepted.
 - We love experimenting with new technologies, and we are especially fond of GitHub Copilot. But as with all new technology, many of us are still getting accustomed to using generative AI tools effectively. Here are important guidelines to follow when using generative AI to contribute to this repository (adapted from the [GitHub Community Discussions CoC](https://github.com/community/community/blob/main/CODE_OF_CONDUCT.md#reasonable-use-of-ai-generated-content)):
   - Read and revise the content before you post it. Use your own authentic voice and edit.
   - Do not post AI-generated content verbatim to pad out the size and number of your contributions. Your changes should materially improve the site, not just say the same thing in different words.