step 1: create a fork of opensourceideas repository by clicking fork button

fork

step 2: go to your fork

step 3: go to content/ideas path

step 4: add a markdown with the filename your_idea.md

step 5: add those lines in the markdown file:

+++
title = 'title_of_your_post'
date = date_of_your_post_with_format_YYYY-MM-DD
+++

step 6: Create a Pull request