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/FieldCheckbox.jsx

@@ -0,0 +1,34 @@
+import React from 'react'
+import PropTypes from 'prop-types'
+
+export default class FieldCheckbox extends React.Component {
+  static propTypes = {
+    value: PropTypes.bool,
+    style: PropTypes.object,
+    onChange: PropTypes.func,
+  }
+
+  static defaultProps = {
+    value: false,
+  }
+
+  render() {
+    return <label className="maputnik-checkbox-wrapper">
+      <input
+        className="maputnik-checkbox"
+        type="checkbox"
+        style={this.props.style}
+        onChange={e => this.props.onChange(!this.props.value)}
+        checked={this.props.value}
+      />
+      <div className="maputnik-checkbox-box">
+        <svg style={{
+            display: this.props.value ? 'inline' : 'none'
+          }} className="maputnik-checkbox-icon" viewBox='0 0 32 32'>
+          <path d='M1 14 L5 10 L13 18 L27 4 L31 8 L13 26 z' />
+        </svg>
+      </div>
+    </label>
+  }
+}
+