disallow irrelevant pages by default in robots

Update default robots.txt rules to disallow irrelevant pages that search
engines should not care about. This will still allow important pages
like the files, commit details, merge requests, issues, comments, etc.
to be crawled.

CHANGELOG

 Please view this file on the master branch, on stable branches it's out of date.
 
 v 7.14.0 (unreleased)
+  - Update default robots.txt rules to disallow crawling of irrelevant pages (Ben Bodenmiller)
   - Upgrade gitlab_git to 7.2.14 to ignore CRLFs in .gitmodules (Stan Hu)
   - Provide more feedback what went wrong if HipChat service failed test (Stan Hu)
   - Fix bug where backslashes in inline diffs could be dropped (Stan Hu)

public/robots.txt

-# See http://www.robotstxt.org/wc/norobots.html for documentation on how to use the robots.txt file
+# See http://www.robotstxt.org/robotstxt.html for documentation on how to use the robots.txt file
 #
 # To ban all spiders from the entire site uncomment the next two lines:
 # User-Agent: *
 # Disallow: /
+
+User-Agent: *
+
+# Add a 1 second delay between successive requests to the same server, limits resources used by crawler
+# Only some crawlers respect this setting, e.g. Googlebot does not
+# Crawl-delay: 1
+
+# Based on details in https://gitlab.com/gitlab-org/gitlab-ce/blob/master/config/routes.rb, https://gitlab.com/gitlab-org/gitlab-ce/blob/master/spec/routing, and using application
+Disallow: /autocomplete/users
+Disallow: /search
+Disallow: /api
+Disallow: /admin
+Disallow: /profile
+Disallow: /dashboard
+Disallow: /projects/new
+Disallow: /groups/new
+Disallow: /groups/*/edit
+Disallow: /users
+
+# Global snippets
+Disallow: /s
+Disallow: /snippets/new
+Disallow: /snippets/*/edit
+Disallow: /snippets/*/raw
+
+# Project details
+Disallow: /*/*.git
+Disallow: /*/*/fork/new
+Disallow: /*/*/repository/archive*
+Disallow: /*/*/activity
+Disallow: /*/*/new
+Disallow: /*/*/edit
+Disallow: /*/*/raw
+Disallow: /*/*/blame
+Disallow: /*/*/commits/*/*
+Disallow: /*/*/commit
+Disallow: /*/*/compare
+Disallow: /*/*/branches/new
+Disallow: /*/*/tags/new
+Disallow: /*/*/network
+Disallow: /*/*/graphs
+Disallow: /*/*/milestones/new
+Disallow: /*/*/milestones/*/edit
+Disallow: /*/*/issues/new
+Disallow: /*/*/issues/*/edit
+Disallow: /*/*/merge_requests/new
+Disallow: /*/*/merge_requests/*.patch
+Disallow: /*/*/merge_requests/*.diff
+Disallow: /*/*/merge_requests/*/edit
+Disallow: /*/*/merge_requests/*/diffs
+Disallow: /*/*/project_members/import
+Disallow: /*/*/labels/new
+Disallow: /*/*/labels/*/edit
+Disallow: /*/*/wikis/*/edit
+Disallow: /*/*/snippets/new
+Disallow: /*/*/snippets/*/edit
+Disallow: /*/*/snippets/*/raw
+Disallow: /*/*/deploy_keys
+Disallow: /*/*/hooks
+Disallow: /*/*/services
+Disallow: /*/*/protected_branches