Replace Haml with Hamlit
What this change does:
- It replaces HAML with [Hamlit](https://github.com/k0kubun/hamlit), a much more efficient implementation of HAML.
- It removes `haml-rails`.
- It adds `hamlit.rb` and removes `haml.rb`.
- It makes things faster and less memory-hungry!
See also #13201.
See merge request !3666
Update docs based on customer upgrade from 4.0
## What does this MR do?
Adds helpful notes to early upgrade docs. Without these helpful hints it will be really hard for most people to upgrade from early versions to later versions.
The tip about doing database migrations to version 6.1, then migrating iids, then migrating the database all the way was based on a tip from https://github.com/gitlabhq/gitlabhq/issues/7869. It worked really well!
See merge request !4409
Update Todos documentation and screenshots to include new functionality.
Updates documentation for todos, includes updated and new screenshots.
See also !4502 and #18906Closes#18923
[ci skip]
See merge request !4840
Clarify artifact expiry
## What does this MR do?
Clarifies documentation about artifact expiry.
## Are there points in the code the reviewer needs to double check?
## Why was this MR needed?
## What are the relevant issue numbers?
## Screenshots (if relevant)
See merge request !4831
Document `GIT_STRATEGY` and `GIT_DEPTH`
## What does this MR do?
Documents `GIT_STRATEGY` and `GIT_DEPTH`. Also fixes the TOC since the anchors weren't working.
## Are there points in the code the reviewer needs to double check?
The TOC and the location of the new entries.
## Why was this MR needed?
## What are the relevant issue numbers?
https://gitlab.com/gitlab-org/gitlab-ci-multi-runner/merge_requests/188
## Screenshots (if relevant)
/cc @axil @ayufan
See merge request !4720
Expand on Award Emoji documentation, update/add screenshots.
Adds documentation for award emoji now that comments can be awarded with emojis.
See also !4291 and #18906Closes#9091
cc: @virtuacreative @axil
See merge request !4839
Add some docs for Docker Registry configuration - Relatively important for anyone installing from source
There have been a few issues created because of the lack of documentation for how to configure Docker Registry when installing from source, specifically what the `realm` needs to be and the `service`
These 2 bits of info will stop a lot of headaches 👍
Issues:
https://gitlab.com/gitlab-org/gitlab-ce/issues/17957https://gitlab.com/gitlab-org/gitlab-ce/issues/17991
See merge request !4738
* Adds pipelines page to CI docs.
* Adds image of pipelines list (although currently missing border that is on other images).
* Changes CI to CI/CD in `/doc` and `/doc/ci`
* Sorts user documentation in `/doc`
Partially fixes#17733.
See merge request !4660
Achilleas Pipinellis
Rémy Coutable
Robert Speicher
Connor Shea
Marc Siegfriedt
Yorick Peterse
Drew Blessing
Drew Blessing
Stan Hu
Marin Jankovski
James Lopez
Mark Pundsack
DJ Mountney
James LopezandAchilleas Pipinellis