drop config/initializers/categories.rb

Once upon a time this was supposed to generate the `/docs`
index page, but it hasn't been used since b4fc467 (pulled in
jasons changes, moving to using his haml directly,
2012-03-29).

Let's drop it, since it creates hassle when updating the
command list.

config/initializers/categories.rb

@@ -1,35 +0,0 @@
-module Gitscm
-  CATEGORIES = [
-    ['Setup and Config',
-      ['git-config', 'git-help']
-    ],['Getting and Creating Projects',
-      ['git-init', 'git-clone']
-    ],['Basic Snapshotting',
-      ['git-add', 'git-status', 'git-diff', 'git-commit', 'git-reset', 'git-rm', 'git-mv']
-    ],['Branching and Merging',
-      ['git-branch', 'git-checkout', 'git-merge',
-       'git-mergetool', 'git-log', 'git-stash', 'git-tag', 'git-worktree']
-    ],['Inspection and Comparison',
-      ['git-show', 'git-log', 'git-diff', 'git-describe']
-    ],['Patching',
-      ['git-am', 'git-apply', 'git-cherry-pick', 'git-rebase']
-    ],['Debugging',
-      ['git-bisect', 'git-blame']
-    ],['Email Workflow',
-      ['git-am', 'git-apply', 'git-format-patch', 'git-send-email', 'git-request-pull']
-    ],['External Systems',
-      ['git-svn', 'git-fast-import']
-    ],['Administration',
-      ['git-clean', 'git-gc', 'git-fsck', 'git-reflog', 'git-filter-branch', 'git-instaweb', 'git-archive', 'git-bundle']
-    ],['Server Admin',
-      ['git-daemon', 'git-update-server-info']
-    ],['Plumbing Commands',
-      ['git-cat-file', 'git-check-ignore','git-commit-tree', 'git-count-objects', 'git-diff-index',
-       'git-diff-tree', 'git-hash-object', 'git-merge-base', 'git-read-tree',
-       'git-rev-list', '']
-    ],['Guides',
-      ['git-attributes', 'git-everyday', 'git-glossary', 'git-ignore',
-       'git-modules', 'git-revisions', 'git-tutorial', 'git-workflows']
-    ]
-  ]
-end