Document a policy about fishing expeditions

Summary:
Tighten the Phabricator support policy from "we will help with literally anything for free" to "we will help with anything for free, except unreproducible fishing expeditions".

This is not the right policy in the long term (in some form, I expect the level of free support will decrease, and, e.g., I won't be offering to drive to your place and fix your stuff), but this class of issue is by far the worst and most pressing and I want to stop dealing with fishing expeditions like this one right now, since I hate supporting them and they're a disproportionately huge waste of time:

  https://github.com/facebook/phabricator/issues/233

We had a similar case over the weekend on Facebook:

  (... snip many messages ...)
  Adam Aahil
  :(
  need your help bro i have to also setup on live server as well
  still trying ...
  not success
  after doing this my local apache is not restarting ..

  Adam Aahil
  when u get time plz let me know

Write a friendly explanation of why these support cases aren't a priority and how to build repro cases.

If this looks good, I plan to respond to anything that I can't reproduce in a few minutes with a link to this.

Test Plan: {F24759}

Reviewers: btrahan, chad

Reviewed By: chad

CC: vrana, aran

Differential Revision: https://secure.phabricator.com/D3981

src/docs/feedback.diviner

@@ -50,6 +50,95 @@ questions and get support.
 
 You can email us at `btrahan@phacility.com` and `epriestley@phacility.com`.
 
+= Filing Good Feature Requests =
+
+When filing a feature request, please provide as much information as possible,
+especially about what your use case is and why you want the feature. Explaining
+what your larger goals are is very helpful, and lets us design better features.
+Tell us what your problem is before you tell us your idea to solve it: sometimes
+we can come up with a better approach to the problem, a slightly different
+approach that solves more problems or helps other users, or a way to make the
+problem go away entirely.
+
+= Filing Good Bug Reports =
+
+When filing a bug report, please provide as much information as possible. In
+particular:
+
+  - If you received an error message, please please please provide it! It is
+    often incredibly useful. See @{article:Please Please Please}.
+  - The second most useful thing to us is reproduction steps. If at all
+    possible, provide a brief list of steps required to reproduce the problem.
+  - If something you didn't expect (other than a crash or obvious error)
+    happened, tell us what you expected and what actually happened.
+
+We can fix clearly-described bugs with reproduction steps and error messages
+much more quickly than vague bugs we can't reproduce.
+
+In particular, if you don't include error messages, we need to ask you for error
+messages. We will nearly always need to do this, and nearly always be unable
+to continue until you provide them. You'll save everyone time if you spend a
+few extra seconds copy/pasting them in the first place.
+
+Generally, err on the side of giving us too much information. It's much quicker
+and easier for us to filter out information that isn't relevant than it is to
+go back and forth asking you to provide more details.
+
+Tips:
+
+  - For issues with `arc`, you can get more information by running the command
+    with the `--trace` flag. For instance, run `arc diff --trace` instead of
+    `arc diff`. Including this output in your bug report is often helpful.
+  - For issues with Phabricator, check your webserver error logs for more
+    information. For Apache, this is usually `/var/log/httpd/error.log` or
+    `/var/log/apache2/error.log`.
+  - For issues with the UI, check your Javascript error console in your browser.
+  - Some other things, like daemons, have debug flags or troubleshooting steps
+    covered in their documentation. Enabling these flags may give you more
+    information about the problem.
+
+= Unreproducible Problems =
+
+Before we can fix a bug, we need to reproduce it. If we can't reproduce a
+problem, we can't tell if we've fixed it and often won't be able to figure out
+why it is occurring.
+
+Most problems reproduce easily, but some are more difficult to reproduce. We
+will generally make a reasonable effort to reproduce problems, but sometimes
+we will be unable to reproduce an issue.
+
+Many of these unreproducible issues turn out to be bizarre environmental
+problems that are unique to one user's install, and figuring out what is wrong
+takes a very long time with a lot of back and forth as we ask questions to
+narrow down the cause of the problem. When we eventually figure it out and fix
+it, few others benefit (in some cases, no one else). This sort of fishing
+expedition is not a good use of anyone's time, and it's very hard for us to
+prioritize solving these problems because they represent a huge effort for very
+little benefit. These problems are a tiny fraction of requests (maybe 1-2%) but
+take up the vast majority of our support effort (maybe 80%).
+
+**If you want us to fix a bug we can't reproduce, you need to build us a working
+reproduction case.** Generally, this means a `root` login on a machine where the
+issue occurs. For example:
+
+  - Bring up a new machine (e.g., in EC2), install Phabricator on it, configure
+    it so the problem is reproducible, and then give us access to it.
+  - If the machine Phabricator is running on is nonessential/nonsensitive and
+    you're comfortable with us having root on it, give us credentials.
+  - If the issue is with Git, SVN or Mercurial, create a new empty repository,
+    add a commit or series of commits which replicate the issue, and give us
+    a zip/tarball of the repository as a reproduction case.
+  - If you're in the San Francisco bay area, we can probably swing by and fix
+    the issue onsite.
+
+These are all fairly heavyweight and will take some time, but often //less//
+of your time than a fishing expedition. If you can build a reproduction case,
+there is a very high chance we can resolve your problem quickly.
+
+Alternatively, you can pay us an enormous pile of money for some kind of
+enterprise support thing and we'd be thrilled to go fishing with you for as long
+as you remain solvent. Email us (see above) for specifics.
+
 = Next Steps =
 
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