Wiki pages list is hard to use with large Wikis
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### Summary
The Wiki pages list is hard to use with more than a dozen pages. For instance, compare GHC's current [Trac wiki index](https://ghc.haskell.org/trac/ghc/wiki/TitleIndex) with the [GitLab index](https://gitlab.staging.haskell.org/ghc/ghc/wikis/pages). While the former isn't particularly pretty, it serves it's purpose: it can be easily scanned by eye to get a sense for the structure and nature of the content in the wiki.
By comparison the latter falls short in a number of areas:
* pagination breaks flow: one can't get a sense of the global structure of the wiki since it is broken across countless pages
* too little information in too much space: visual scanning is difficult due to the large amount of padding between items and distracting horizontal rules
* lost hierarchy: while in Trac you can easily skip entire subtrees, in GitLab's index you are forced to look at every entry
### Steps to reproduce
Create a large wiki (e.g. )
### Example Project
Here is GHC's current Wiki: https://github.com/bgamari/ghc-wiki-import
### What is the current *bug* behavior?
It's nearly impossible to find content unless you know of a search keyword.
### What is the expected *correct* behavior?
It should be possible to get a sense of the structure of the wiki.
format console output,
logs, and code as it's very hard to read otherwise.)
### Output of checks
This bug happens on GitLab.com
### Possible fixes
These three changes would greatly improve the situation:
* Eliminate pagination
* Render the list as a tree (perhaps with [guides](http://cssdeck.com/labs/pure-css-tree-menu-framework) to help the eye follow the structure)
* Cut the vertical padding in half, eliminate the horizontal rules
* Drop the parenthesized format
issue