Add publishing/installing docs

Summary:
Adding publishing and installation procedure docs to
our tutorial to round things off.

Reviewed By: jknoxville

Differential Revision: D17711800

fbshipit-source-id: 57c848c559208eb2a0ca790a72bcd493730baf16

docs/tutorial/js-publishing.md

@@ -0,0 +1,55 @@
+---
+id: js-publishing
+title: Publishing your Plugin
+sidebar_label: Publishing
+---
+
+Once you're happy with your plugin and want the world to see it,
+you can publish it to npm. Ensure that your plugin follows these
+two rules:
+
+- The package name should to start with "flipper-plugin-". This makes
+  it easier to see what the purpose of the package is.
+- The package must include the keyword "flipper-plugin".
+
+A valid example `package.json` could look like this:
+
+```json
+{
+  "name": "flipper-plugin-example",
+  "version": "1.0.0",
+  "description": "An example for a Flipper plugin",
+  "main": "index.tsx",
+  "license": "MIT",
+  "keywords": ["flipper-plugin"],
+  "title": "Example Plugin",
+  "icon": "apps",
+  "bugs": {
+    "url": "https://github.com/facebook/flipper/issues/"
+  }
+}
+```
+
+When you have confirmed that your `package.json` is correct,
+run `yarn publish` or `npm publish` and follow the instructions.
+
+## Installing Plugins
+
+Once your plugin is published you can find it, alongside other
+available Flipper plugins, by clicking on "Manage Plugins..."
+in the bottom of the left sidebar and selecting the
+"Install Plugins" tab. It may take a few moments for the
+search index to update and your plugin to appear.
+
+![Install plugins](/docs/assets/install-plugins.png)
+
+## Native Distribution
+
+Depending on whether the client-side part of your plugin targets
+Android, iOS or React Native, we recommend you use the standard
+package distribution mechanism for the platform.
+
+This may be Maven Central, JCenter or GitHub Packages for Android,
+CocoaPods for iOS and npm or GitHub Packages for React Native.
+Make sure to leave setup instructions in the README of your
+npm package.