Tidy of components

- Moved all components into a single directory like nextjs
 - Made component names consistent with each other
 - Made component names consistent with their export class names
 - Added storybook for a few components with the aim to extend this further.

src/components/FieldDocLabel.jsx

@@ -0,0 +1,63 @@
+import React from 'react'
+import PropTypes from 'prop-types'
+
+import {MdInfoOutline, MdHighlightOff} from 'react-icons/md'
+
+export default class FieldDocLabel extends React.Component {
+  static propTypes = {
+    label: PropTypes.oneOfType([
+      PropTypes.object,
+      PropTypes.string
+    ]).isRequired,
+    fieldSpec: PropTypes.object,
+    onToggleDoc: PropTypes.func,
+  }
+
+  constructor (props) {
+    super(props);
+    this.state = {
+      open: false,
+    }
+  }
+
+  onToggleDoc = (open) => {
+    this.setState({
+      open,
+    }, () => {
+      if (this.props.onToggleDoc) {
+        this.props.onToggleDoc(this.state.open);
+      }
+    });
+  }
+
+  render() {
+    const {label, fieldSpec} = this.props;
+    const {doc} = fieldSpec || {};
+
+    if (doc) {
+      return <label className="maputnik-doc-wrapper">
+        <div className="maputnik-doc-target">
+          {label}
+          {'\xa0'}
+          <button
+            aria-label={this.state.open ? "close property documentation" : "open property documentation"}
+            className={`maputnik-doc-button maputnik-doc-button--${this.state.open ? 'open' : 'closed'}`}
+            onClick={() => this.onToggleDoc(!this.state.open)}
+          >
+            {this.state.open ? <MdHighlightOff /> : <MdInfoOutline />}
+          </button>
+        </div>
+      </label>
+    }
+    else if (label) {
+      return <label className="maputnik-doc-wrapper">
+        <div className="maputnik-doc-target">
+          {label}
+        </div>
+      </label>
+    }
+    else {
+      <div />
+    }
+  }
+}