Summary:
**Summary**

This PR, similarly to https://github.com/facebook/react-native-website/pull/1337, adds [alexjs](https://alexjs.com/) linting to Draft.js in order to identify and prevent insensitive and inconsiderate language from landing on master.

- Adds Alex
- Configures Alex rules
- **TODO:** Run Alex in Travis CI

**Test Plan**

- Run `yarn lint-docs`
- Verify there are no lint violations
Pull Request resolved: https://github.com/facebook/draft-js/pull/2223

Differential Revision: D18046996

Pulled By: claudiopro

fbshipit-source-id: 66ac935720a0b13576e9a133a3d5f8e98cc539cf

Summary:
Fixes https://github.com/facebook/draft-js/issues/2144

**Summary**
Previous jsfiddle links were using old versions of React and Draft.

Feel free to reject if you actually have access to previous fiddles and update the libs there.
Pull Request resolved: https://github.com/facebook/draft-js/pull/2145

Reviewed By: claudiopro

Differential Revision: D16545086

Pulled By: gmertk

fbshipit-source-id: 2450a17e0005f984dffd3e7c75b792c4edab3ef8

Summary:
**Summary**
Changes reference to the BSD license to MIT in the contributing guidelines. Fixes https://github.com/facebook/draft-js/issues/2129

**Test Plan**
Proofreading
Pull Request resolved: https://github.com/facebook/draft-js/pull/2130

Reviewed By: niveditc

Differential Revision: D16286748

Pulled By: claudiopro

fbshipit-source-id: 3700f15d32fd2b1527135e8f432600009051208e

Summary:
**Summary**

We've been loosely following these guidelines for the past month & they seem to be working well. Adding to `CONTRIBUTING.md` to make it more visible.

**Test Plan**
<img width="793" alt="screenshot 2018-10-14 12 54 05" src="https://user-images.githubusercontent.com/2357761/46921447-40040880-cfb0-11e8-8e74-386c17a4778e.png">
Pull Request resolved: https://github.com/facebook/draft-js/pull/1896

Differential Revision: D10382836

fbshipit-source-id: e96336a96f27681b59510fcd15baa30e146ed631

* Add Code of Conduct to CONTRIBUTING doc

Good stuff. Snagged from the
[React 'How to Contribute'](https://facebook.github.io/react/contributing/how-to-contribute.html)
page.

* Add stability philosophy to CONTRIBUTING doc

To address questions and concerns we have had internally and externally
about API changes.

* Fix missing newline

Thanks to @existentialism for catching this.

Just another nudge to help folks with showing how a bug is reproduced.