Copy contributing doc instead of moving

Author: detrumi

CONTRIBUTING.md

@@ -1 +1,95 @@
-For information on how to help contribute to chalk, see the [contribution guide](https://rust-lang.github.io/chalk/book/contribution_guide.html) in the chalk book
+# Contributing to chalk
+
+Thank you for your interest in contributing to chalk! There are many ways to
+contribute, and we appreciate all of them.
+
+* [Bug Reports](#bug-reports)
+* [Running and Debugging](#running-and-debugging)
+* [Pull Requests](#pull-requests)
+* [Writing Documentation](#writing-documentation)
+* [Helpful Links and Information](#helpful-links-and-information)
+
+If you'd like to contribute, consider joining the [Traits Working Group][traits-working-group].
+We hang out on the [rust-lang zulip][rust-lang-zulip] in the [#wg-traits][wg-traits-stream] stream.
+
+As a reminder, all contributors are expected to follow our [Code of Conduct][coc].
+
+[traits-working-group]: https://rust-lang.github.io/compiler-team/working-groups/traits/
+[rust-lang-zulip]:https://rust-lang.zulipchat.com
+[wg-traits-stream]: https://rust-lang.zulipchat.com/#narrow/stream/144729-wg-traits
+[coc]: https://www.rust-lang.org/conduct.html
+
+## Bug Reports
+[bug-reports]: #bug-reports
+
+While bugs are unfortunate, they're a reality in software. We can't fix what we
+don't know about, so please report liberally. If you're not sure if something
+is a bug or not, feel free to file a bug anyway.
+
+If you have the chance, before reporting a bug, please search existing issues,
+as it's possible that someone else has already reported your error. This doesn't
+always work, and sometimes it's hard to know what to search for, so consider
+this extra credit. We won't mind if you accidentally file a duplicate report.
+
+Sometimes, a backtrace is helpful, and so including that is nice. To get
+a backtrace, set the `RUST_BACKTRACE` environment variable to a value
+other than `0`. The easiest way to do this is to invoke `chalk` like this:
+
+```bash
+$ RUST_BACKTRACE=1 chalk ...
+```
+
+## Running and Debugging
+[running-and-debugging]: #running-and-debugging
+There is a repl mainly for debugging purposes which can be run by `cargo run`. Some basic examples are in [libstd.chalk](libstd.chalk):
+```bash
+$ cargo run
+?- load libstd.chalk
+?- Vec<Box<i32>>: Clone
+Unique; substitution [], lifetime constraints []
+```
+
+More logging can be enabled by setting the `CHALK_DEBUG` environment variable. Set `CHALK_DEBUG=1` to see `info!(...)` output, and `CHALK_DEBUG=2` to see `debug!(...)` output as well.
+
+## Pull Requests
+[pull-requests]: #pull-requests
+
+Pull requests are the primary mechanism we use to change Rust. GitHub itself
+has some [great documentation][pull-request-documentation] on using the Pull Request feature.
+We use the "fork and pull" model [described here][development-models], where
+contributors push changes to their personal fork and create pull requests to
+bring those changes into the source repository.
+
+Please make pull requests against the `master` branch.
+
+[pull-request-documentation]: https://help.github.com/articles/about-pull-requests/
+[development-models]: https://help.github.com/articles/about-collaborative-development-models/
+
+## Writing Documentation
+[writing-documentation]: #writing-documentation
+
+Documentation improvements are very welcome. Documentation pull requests
+function in the same way as other pull requests.
+
+You can find documentation style guidelines in [RFC 1574][rfc1574].
+
+[rfc1574]: https://github.com/rust-lang/rfcs/blob/master/text/1574-more-api-documentation-conventions.md#appendix-a-full-conventions-text
+
+## Helpful Links and Information
+[Helpful Links and Information]: #helpful-links-and-information
+
+### Blog posts
+There are several [blog posts][blog-posts] which describe the ideas and
+machinery inside of chalk.
+
+[blog-posts]: README.md#blog-posts
+
+### Glossary
+
+In addition to the blog posts there is a [glossary](GLOSSARY.md) explaining some
+of the terminology used in chalk.
+
+### Trait solving in rustc-dev-guide
+The rustc-dev-guide describes [new-style trait solving][trait-solving], which is slowly replacing the old trait resolution.
+
+[trait-solving]: https://rustc-dev-guide.rust-lang.org/traits/index.html