Open-sourcing the Gitter mobile apps

What this post added

This post details the technical steps taken to open-source the Gitter Android and iOS mobile applications. This includes using truffleHog to find and remove secrets from the repository history, implementing a secrets.properties file and environment variables for build configurations, and utilizing BFG Repo-Cleaner to rewrite Git history. For the iOS app, manual secret searching was employed due to Xcode-generated files. The process also involved removing compiled assets from the webapp and managing OAuth secrets within a shared submodule.