Upgrade static docs plugin

Summary:
Upgrade the static docs plugin.

You no longer need to import OssOnly and FbInternalOnly in markdown files, so removed those imports too.

Reviewed By: passy

Differential Revision: D26580059

fbshipit-source-id: 2763de2f5fbef41ec2ac7f7bdd147418badb78b6

docs/extending/desktop-plugin-structure.mdx

@@ -3,7 +3,6 @@ id: desktop-plugin-structure
 title: Plugin structure
 ---
 
-import {FbInternalOnly, OssOnly} from 'internaldocs-fb-helpers';
 import FbNpmDeps from '../fb/adding-npm-dependencies-0.mdx'
 
 Flipper Desktop plugins have a rigid structure. We recommend to scaffold any new plugin using our scaffolding tooling.

docs/extending/dev-setup.mdx

@@ -3,8 +3,6 @@ id: dev-setup
 title: Development Setup
 ---
 
-import {FbInternalOnly, OssOnly} from 'internaldocs-fb-helpers';
-
 ## IDE
 
 <OssOnly>

docs/extending/flipper-plugin.mdx

@@ -2,7 +2,6 @@
 id: flipper-plugin
 title: Desktop Plugin API
 ---
-import {FbInternalOnly} from 'internaldocs-fb-helpers';
 
 ## PluginClient
 

docs/extending/loading-custom-plugins.mdx

@@ -3,8 +3,6 @@ id: loading-custom-plugins
 title: Dynamically Loading Plugins
 ---
 
-import {FbInternalOnly, OssOnly} from 'internaldocs-fb-helpers';
-
 <FbInternalOnly>
 
 <div class="warning">

docs/extending/plugin-distribution.mdx

@@ -3,7 +3,6 @@ id: plugin-distribution
 title: Plugin Distribution
 ---
 
-import {FbInternalOnly, OssOnly} from 'internaldocs-fb-helpers';
 import FbPluginReleases from './fb/desktop-plugin-releases.mdx'
 
 <OssOnly>

docs/extending/testing.mdx

@@ -5,7 +5,6 @@ title: Testing
 
 import Tabs from '@theme/Tabs';
 import TabItem from '@theme/TabItem';
-import {FbInternalOnly, OssOnly} from 'internaldocs-fb-helpers';
 import FbIosTesting from '../fb/ios-plugin-development-testing-ios-plugins-0.mdx';
 import FbAndroidTesting from '../fb/android-plugin-development-testing-android-plugins-0.mdx';