Yarn workspaces

Summary:
1) moved "sonar/desktop/src" to "sonar/desktop/app/src", so "app" is now a separate package containing the core Flipper app code
2) Configured yarn workspaces with the root in "sonar/desktop": app, static, pkg, doctor, headless-tests. Plugins are not included for now, I plan to do this later.

Reviewed By: jknoxville

Differential Revision: D20535782

fbshipit-source-id: 600b2301960f37c7d72166e0d04eba462bec9fc1

desktop/app/src/ui/components/Link.tsx

@@ -0,0 +1,41 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ */
+
+import styled from '@emotion/styled';
+import {colors} from './colors';
+import {Component} from 'react';
+import {shell} from 'electron';
+import React from 'react';
+
+const StyledLink = styled.span({
+  color: colors.highlight,
+  '&:hover': {
+    cursor: 'pointer',
+    textDecoration: 'underline',
+  },
+});
+StyledLink.displayName = 'Link:StyledLink';
+
+export default class Link extends Component<{
+  href: string;
+  children?: React.ReactNode;
+  style?: React.CSSProperties;
+}> {
+  onClick = () => {
+    shell.openExternal(this.props.href);
+  };
+
+  render() {
+    return (
+      <StyledLink onClick={this.onClick} style={this.props.style}>
+        {this.props.children || this.props.href}
+      </StyledLink>
+    );
+  }
+}