Added a How To File GitHub Issues guide

See https://github.com/ipfs/go-ipfs/pull/2786

License: MIT
Signed-off-by: Richard Littauer <richard.littauer@gmail.com>

docs/github-issue-guide.md

+# How to file a GitHub Issue
+
+We use GitHub Issues to log all of our todos and tasks. Here is [a good guide](https://guides.github.com/features/issues/) for them if you are unfamiliar.
+
+When logging an issue with go-ipfs, it would be useful if you specified the below information, if possible. This will help us triage the issues faster. Please title your issues with the type. For instance:
+
+- "bug: Cannot add file with `ipfs add`"
+- "question: How do I use `ipfs block <hash>`?"
+
+Putting the command in backticks helps us parse the natural language description, and is generally suggested.
+
+This is a _living guide_. If you see anything that should be here and isn't, or have ideas on improvement, please open a "meta" issue.
+
+### Type
+
+- "bug": If what you are filing is a bug.
+- "meta": If it is something about how we run go-ipfs, and not code related in itself.
+- "question": If you have a question.
+- "test failure": If the tests are failing
+- "panic": If it is a severe bug.
+- "enhancement ": If you have a feature you would like that enhances go-ipfs.
+
+### Platform
+
+For platform and processor, just run `ipfs version --all` and include that output.
+
+Your platform.
+
+- "Linux"
+- "Windows"
+- "Mac"
+- Etc.
+
+### Processor
+
+Your processor.
+
+- "x86"
+- "amd64"
+- "Arm"
+
+### Area
+
+What your issue refers to. Multiple items are OK.
+
+- "api"
+- "bandwidth reduction"
+- "bit swap"
+- "blockstore"
+- "commands"
+- "containers + vms"
+- "core"
+- "daemon + init"
+- "dat"
+- "discovery"
+- "encryption"
+- "files"
+- "fuse"
+- "gateway"
+- "gx"
+- "interior"
+- "pins"
+- "libp2p"
+- "merkledag"
+- "nat"
+- "releases"
+- "repo"
+- "routing"
+- "tools"
+- "tracking"
+- "unix vs dag"
+
+### Priority
+
+- "P0 - Operations Functioning"
+- "P1 - Operations Sort of Functioning"
+- "P2 - Operations Not Functioning"
+- "P3 - Operations Foobar (critical bug affecting master)"
+- "P4 - Operations on Fire (critical bug affecting release)"