Add an issue template and CONTRIBUTING.md.

Fixes #332.

CONTRIBUTING.md

+# Contributing
+Contributions of all types are welcome. We use GitHub as our bug and feature tracker both for code and for other
+aspects of the library (documentation, the wiki etc.)
+
+## Asking Questions
+The best way to ask general questions is to send an email to our [mailing list][2], or join [#glide-library on
+freenode.org.][3]
+
+## Filing issues
+To file an issue, please use our [issue template link][1] and fill out the template as much as possible. The more
+information you can provide, the more likely we are to be able help.
+
+When in doubt, file an issue. We'd rather close a few duplicate issues than let a problem go unnoticed. Similarly if
+you support a particular feature request, feel free to let us know by commenting on the issue.
+
+## Contributing code
+Pull requests are welcome for all parts of the codebase, especially the integration libraries. You can find
+instructions on building the project in our README. Our code style is defined in Intellij project files in the repo
+and also by our Checkstyle config. If you'd like to submit code, but can't get the style checks to pass, feel
+free to put up your pull request anyway and we can help you fix the style issues. If you'd like to
+contribute code, you will need to sign [Google's individual contributor license agreement][4].
+
+[1]: https://github.com/bumptech/glide/issues/new?body=**Glide%20Version/Integration%20library%20(if%20any)**:%0A**Device/Android%20Version**:%0A**Issue%20details/Repro%20steps**:%0A%0A**Glide%20load%20line**:%0A```%0AGlide.with(context)...%3B%0A```%0A%0A**Stack%20trace**:%0A```%0Apaste%20stack%20trace%20here%0A```
+[2]: https://groups.google.com/forum/#!forum/glidelibrary
+[3]: http://webchat.freenode.net/?channels=glide-library
+[4]: https://developers.google.com/open-source/cla/individual.

README.md

@@ -155,7 +155,7 @@ anything else, join or email [Glide's discussion group][6], or join our irc chan
 
 Contributing
 ------------
-Before submitting pull requests, contributors must sign Google's [individual contribution license agreement][7].
+Before submitting pull requests, contributors must sign Google's [individual contributor license agreement][7].
 
 Thanks
 ------
@@ -177,7 +177,7 @@ This is not an official Google product.
 [2]: https://github.com/bumptech/glide/wiki
 [3]: http://bumptech.github.io/glide/javadocs/latest/index.html
 [4]: https://www.jetbrains.com/idea/download/
-[5]: https://github.com/bumptech/glide/issues/new
+[5]: https://github.com/bumptech/glide/issues/new?body=**Glide%20Version/Integration%20library%20(if%20any)**:%0A**Device/Android%20Version**:%0A**Issue%20details/Repro%20steps**:%0A%0A**Glide%20load%20line**:%0A```%0AGlide.with(context)...%3B%0A```%0A%0A**Stack%20trace**:%0A```%0Apaste%20stack%20trace%20here%0A```
 [6]: https://groups.google.com/forum/#!forum/glidelibrary
 [7]: https://developers.google.com/open-source/cla/individual
 [8]: https://github.com/JakeWharton/DiskLruCache