An "Everything Bucket" - no, I've tried it and it's too rigid for my needs, and has me duplicating work (which I hate). Here's what I have found works best for me as a project manager/developer:
Trello - for higher level planning, keeping track of things I want to accomplish, and todo lists. I don't pay for their service because you can create private projects without paying.
Waffle - for GitHub Task assignment from the higher level planning done in Trello, and project management because I don't like using Tasks or Projects from within GitHub, so I pay to have a nicer GUI to manage project workflow.
GitHub - backs up my repo's, has wikis to document the project, and keep it together with the repo. I pay so I can keep most of my repo's private.
The above, is more about project management and development workflow, while below is more about what you are asking about which could be all in one, if I could find a plugin to properly display code snippets on WordPress (I have not liked any of the ones I have used over the years).
GitHub Gists - to document code snippets (mostly for referencing to from my blog posts, and also documenting my shell scripts).
Closest thing to an "Everything Bucket" is a WordPress blog where I "document" a lot of stuff that doesn't fit into a GitHub repo (like server admin), and often referencing my GitHub Gists where I find it easier to document code (then within WP blog posts), and also to keep track of links that I find useful so I don't have to deal with another bookmarking service shutting down!