Update docs

* Update README for consistency across all shoulda-* gems
* Add MAINTAINING
* Drop CONTRIBUTING document since this gem is more or less deprecated

[ci skip]

MIT-LICENSE → LICENSE

@@ -1,4 +1,4 @@
-Copyright (c) 2006-2020, Tammer Saleh and thoughtbot, inc.
+Copyright (c) 2006-2020 Tammer Saleh and thoughtbot, inc.
 
 Permission is hereby granted, free of charge, to any person
 obtaining a copy of this software and associated documentation

MAINTAINING.md

@@ -0,0 +1,104 @@
+# Maintaining Shoulda Context
+
+Although Shoulda Context doesn't receive feature updates these days, you may
+need to update the gem for new versions of Ruby or Rails. Here's what you need
+to know in order to do that.
+
+## Getting started
+
+First, run the setup script:
+
+    bin/setup
+
+Then run all the tests to make sure everything is green:
+
+    bundle exec rake
+
+## Running tests
+
+This project uses Minitest for tests and Appraisal to create environments
+attuned for different versions of Rails. To run a single test in a single test
+file, you will need to use a combination of Appraisal and the [`m`][m] gem. For
+instance:
+
+[m]: https://github.com/qrush/m
+
+    bundle exec appraisal rails_6_0 m test/shoulda/context_test.rb:39
+
+## Updating the changelog
+
+After every user-facing change makes it into master, we make a note of it in the
+changelog, kept in `CHANGELOG.md`. The changelog is sorted in reverse order by
+release version, with the topmost version as the next release (tagged as
+"(Unreleased)").
+
+Within each version, there are five available categories you can divide changes
+into. They are all optional but they should appear in this order:
+
+1. Backward-compatible changes
+1. Deprecations
+1. Bug fixes
+1. Features
+1. Improvements
+
+Within each category section, the changes relevant to that category are listed
+in chronological order.
+
+For each change, provide a human-readable description of the change as well as a
+linked reference to the PR where that change emerged (or the commit ID if no
+such PR is available). This helps users cross-reference changes if they need to.
+
+## Versioning
+
+### Naming a new version
+
+As designated in the README, we follow [SemVer 2.0][semver]. This offers a
+meaningful baseline for deciding how to name versions. Generally speaking:
+
+[semver]: https://semver.org/spec/v2.0.0.html
+
+* We bump the "major" part of the version if we're introducing
+  backward-incompatible changes (e.g. changing the API or core behavior,
+  removing parts of the API, or dropping support for a version of Ruby).
+* We bump the "minor" part if we're adding a new feature (e.g. adding a new
+  matcher or adding a new qualifier to a matcher).
+* We bump the "patch" part if we're merely including bugfixes.
+
+In addition to major, minor, and patch levels, you can also append a
+suffix to the version for pre-release versions. We usually use this to issue
+release candidates prior to an actual release. A version number in this case
+might look like `4.0.0.rc1`.
+
+### Preparing and releasing a new version
+
+In order to release any versions at all, you will need to have been added as
+an owner of the Ruby gem. If you want to give someone else these permissions,
+then run:
+
+```bash
+gem owner shoulda-context -a <email address>
+```
+
+Assuming you have permission to publish a new version to RubyGems, then this is
+how you release a version:
+
+1. First, you'll want to [make sure that the changelog is up to
+   date](#updating-the-changelog).
+
+2. Next, you'll want to update the `VERSION` constant in
+   `lib/shoulda/context/version.rb`. This constant is referenced in the
+   gemspec and is used in the Rake tasks to publish the gem on RubyGems.
+
+3. Assuming that everything looks good, place your changes to the changelog,
+   `version.rb`, and README in their own commit titled "Bump version to
+   *X.Y.Z*". Push this to GitHub (you can use `[ci skip]`) in the body of the
+   commit message to skip CI for this commit if you so choose). **There is no
+   going back after this point!**
+
+6. Once GitHub has the version-change commit, you will run:
+
+   ```bash
+   rake release
+   ```
+
+   This will push the gem to RubyGems and make it available for download.

README.md

@@ -20,7 +20,10 @@ fully compatible with your existing tests and requires no retooling to use.
 [rubydocs]: http://rubydoc.info/github/thoughtbot/shoulda-context/master/frames
 [changelog]: CHANGELOG.md
 
-## Usage
+[shoulda-matchers]: https://github.com/thoughtbot/shoulda-matchers
+[minitest_matchers-vaccine]: https://github.com/rmm5t/minitest-matchers_vaccine
+
+## Overview
 
 Instead of writing Ruby methods with `lots_of_underscores`, Shoulda Context lets
 you name your tests and group them together using English.
@@ -138,41 +141,42 @@ may be of use:
 * `assert_reject` — what `should_not` uses internally; asserts that a matcher
   object does not match against a value
 
-## Note on running tests
+## Compatibility
 
-Normally, you will run a single test like this:
+Shoulda Context is [tested][travis] and supported against Ruby 2.4+, Rails 4.2+,
+Minitest 4.x, and Test::Unit 3.x.
 
-    ruby -I lib -I test path_to_test.rb -n name_of_test_method
+## Versioning
 
-When using Shoulda Context, however, you'll need to put a space after the test
-name:
+Shoulda Context follows Semantic Versioning 2.0 as defined at
+<http://semver.org>.
 
-    ruby -I lib -I test path_to_test.rb -n "test_: a calculator should add two numbers for the sum. "
+## Team
 
-If this is too cumbersome, consider using the [m] gem to run tests instead:
+Shoulda Context is maintained by [Elliot Winkler][mcmire]. It was previously
+maintained by [Travis Jeffery][travisjeffery].
 
-    m path_to_test.rb:39
+[mcmire]: https://github.com/mcmire
+[travisjeffery]: https://github.com/travisjeffery
 
-[m]: https://github.com/qrush/m
+## Copyright/License
 
-## Compatibility
+Shoulda Context is copyright © 2006-2020 Tammer Saleh and [thoughtbot,
+inc][thoughtbot-website]. It is free and opensource software and may be
+redistributed under the terms specified in the [LICENSE](LICENSE) file.
 
-Shoulda Context is tested and supported against Rails 4.x+, Minitest 4.x,
-Test::Unit 3.x, and Ruby 2.4+.
+[thoughtbot-website]: https://thoughtbot.com
 
-## Credits
+## About thoughtbot
 
-Shoulda Context is maintained by [Elliot Winkler][elliot-winkler], [Travis
-Jeffery][travis-jeffery], and thoughtbot. Thank you to all the [contributors].
+![thoughtbot][thoughtbot-logo]
 
-[elliot-winkler]: https://github.com/mcmire
-[travis-jeffery]: https://github.com/travisjeffery
-[contributors]: https://github.com/thoughtbot/shoulda-context/contributors
+[thoughtbot-logo]: https://presskit.thoughtbot.com/images/thoughtbot-logo-for-readmes.svg
 
-## License
+The names and logos for thoughtbot are trademarks of thoughtbot, inc.
 
-Shoulda Context is copyright © 2006-2020 [thoughtbot, inc][thoughtbot-website].
-It is free software, and may be redistributed under the terms specified in the
-[MIT-LICENSE](MIT-LICENSE) file.
+We are passionate about open source software. See [our other
+projects][community]. We are [available for hire][hire].
 
-[thoughtbot-website]: https://thoughtbot.com
+[community]: https://thoughtbot.com/community?utm_source=github
+[hire]: https://thoughtbot.com?utm_source=github