Documentation updates

* Add plugin info and more interface descriptions to api.md
* Mention TS reference directives in README
* Add content to reporters section in extending.md
* Update doc formatting

Author: jason0x43

README.md

@@ -20,9 +20,9 @@ Intern is a complete test system for JavaScript designed to help you write and
 run consistent, high-quality test cases for your JavaScript libraries and
 applications. It can be used to test _any_ JavaScript code.
 
-*   Plain JavaScript code, in any module format (or no module format!)
-*   Web pages generated by server-side languages (like Java, PHP, or Ruby)
-*   Native or hybrid iOS, Android, and Firefox OS applications
+- Plain JavaScript code, in any module format (or no module format!)
+- Web pages generated by server-side languages (like Java, PHP, or Ruby)
+- Native or hybrid iOS, Android, and Firefox OS applications
 
 Intern is minimally prescriptive and enforces only a basic set of best practices
 designed to ensure your tests stay maintainable over time. Its extensible
@@ -81,20 +81,27 @@ following to your `tsconfig.json`:
 
 ```json
 {
-    "compilerOptions": {
-        "types": ["intern"]
-    }
+  "compilerOptions": {
+    "types": ["intern"]
+  }
 }
 ```
 
+Alternatively, add a triple-slash directive to the top of your suite files:
+
+```ts
+/// <reference types="intern" />
+```
+
 ## Compatibility
 
 Intern can run unit tests in most browsers that support ECMAScript 5, including
 mobile browsers on Android and iOS, and in Node 6+. Note that Internet Explorer
-9 is currently not supported.
+9 is not supported.
 
-Intern’s self-tests run against IE 10 and 11, Firefox 33 and current, Chrome 38
-and current, and Safari 9 and 10, as well as Node 6 and 8.
+Intern’s self-tests run against IE 10 and 11, Firefox 36 and current, Chrome 38
+and current, and Safari 9 and 10, as well as the latest LTS and current versions
+of Node.
 
 Intern can run functional tests using WebDriver-compatible applications and
 services, including Selenium, Appium, Selendroid. It has built-in support for
@@ -106,24 +113,24 @@ cloud testing services from [BrowserStack](https://browserstack.com),
 
 ## More information
 
-*   [Getting started](docs/getting_started.md) - Setting up Intern to test a
-    project
-*   [Changes from Intern 3](docs/changes_from_3.md) - Major changes from Intern
-    3 to Intern 4
-*   [How To](docs/how_to.md) - Quick answers to common questions
-*   [Concepts](docs/concepts.md) - General testing concepts and definitions
-*   [Architecture](docs/architecture.md) - How Intern is organized
-*   [Configuration](docs/configuration.md) - How to configure Intern
-*   [Writing tests](docs/writing_tests.md) - The various ways of writing tests
-    with Intern
-*   [Running](docs/running.md) - How to run Intern
-*   [Extending](docs/extending.md) - Extending Intern with reporters and other
-    plugins
-*   [API](docs/api.md) - Summary API documentation
-*   [Continuous integration](docs/ci.md) - Using Intern with CI systems
-*   [Developing](docs/developing.md) - For Intern developers
-*   [Contributing](CONTRIBUTING.md) - How to contribute to Intern development
-    <!-- end-github-only -->
+- [Getting started](docs/getting_started.md) - Setting up Intern to test a
+  project
+- [Changes from Intern 3](docs/changes_from_3.md) - Major changes from Intern 3
+  to Intern 4
+- [How To](docs/how_to.md) - Quick answers to common questions
+- [Concepts](docs/concepts.md) - General testing concepts and definitions
+- [Architecture](docs/architecture.md) - How Intern is organized
+- [Configuration](docs/configuration.md) - How to configure Intern
+- [Writing tests](docs/writing_tests.md) - The various ways of writing tests
+  with Intern
+- [Running](docs/running.md) - How to run Intern
+- [Extending](docs/extending.md) - Extending Intern with reporters and other
+  plugins
+- [API](docs/api.md) - Summary API documentation
+- [Continuous integration](docs/ci.md) - Using Intern with CI systems
+- [Developing](docs/developing.md) - For Intern developers
+- [Contributing](CONTRIBUTING.md) - How to contribute to Intern development
+  <!-- end-github-only -->
 
 ## Get help