Contributing Guide for 1.0 (#727)

* Added Lerna instructions and updated contributing guide for 1.0.

* Added link command for gatsby specifically.

* Yarn install needs to be run in project root as well.

* Symlinked CONTRIBUTING.md to how-to-contribute.md so this shows up on the docs site.

* Updated standard steps for getting started.

* Updating heading styles to match the docs site.

* Added 'run' to commands and made the purpose of the initial 'build' command more apparent.

CONTRIBUTING.md

@@ -1,34 +1,37 @@
-# Filing an issue
+# How to contribute
+
+## Filing an issue
 
 If you want your issue to be resolved quickly, please include in your
 issue:
 
 * Gatsby version, node.js version, OS version
 * The contents of your `gatsby-node.js`, `gatsby-browser.js`, and `package.json`.
 
-# Contributing
+## Contributing
 You can install the latest `master` version of Gatsby by following these
 simple steps:
 
 * Clone the repo, navigate to its directory.
-* Execute `npm install` to install packages.
-* Execute `npm uninstall -g gatsby && npm link`
+* Install Lerna if you don't have it already: `yarn global add lerna@^2.0.0-beta.0`
+* Execute `yarn && lerna bootstrap` to install dependencies and cross link all the packages.
 * Use `git pull` to update to latest Gatsby.
 
-Test suite can be run via `npm test`.
+Test suite can be run via `yarn test`.
 
 This project uses [FlowType](https://flowtype.org/) for static type checking.
 
 The usual contributing steps are:
 
 * Fork the [official repository](https://github.com/gatsbyjs/gatsby).
 * Clone your fork: git clone `git@github.com:<your-username>/gatsby.git`
-* Make sure tests are passing for you: npm install && npm test
-* Create a topic branch: git checkout -b topics/new-feature-name
-* Run `npm run watch` to watch code and compile your changes.
-* Clone one of the official repositories and "link" your fork of Gatsby
-  to it (run `npm link gatsby`).
+* Install dependencies: `yarn && lerna bootstrap`
+* Make sure tests are passing for you: `lerna run test`
+* Create a topic branch: `git checkout -b topics/new-feature-name`
+* Run `yarn run build` to do an initial build and ensure there are no errors.
+* Run `yarn run watch` to watch code and compile your changes on the fly as you work.
+* Symlink the built file from whatever plugin you're trying to modify (will be in `packages/package-name`) into your project's `node_modules/package-name` directory to avoid getting the node_modules folder coming across to your site.
 * Add tests and code for your changes.
-* Once you‘re done, make sure all tests still pass: npm install && npm test
+* Once you‘re done, make sure all tests still pass: `yarn test`
 * Commit and push to your fork.
 * Create an pull request from your branch.

docs/docs/how-to-contribute.md

@@ -0,0 +1 @@
+../../CONTRIBUTING.md