Fix the redirect issue on the home page topics

[farbodsaraf]

Currently when users land on the home page, if they click on one of the item in the topic list, after navigating to a policy in a certain topic, the user will be redirected to a wrong URL.

[farbodsaraf]

Steps to reproduce:

• Navigate to the home page.
• Click on one of the "Naming Convention topic list" on the home page.
• Navigate to a policy under a topic
• The website eats part of the URL and navigate to something like: https://namingconvention.org/package-naming.html

[sandoche]

Fixed

[farbodsaraf]

he link for the contribution guide on the main page is broken. It goes to CONTRIBUTING.md instead of CONTRIBUTING.html.

[sandoche]

Fixed pushed to dev branch !