Fix: Replace 'walkes' with 'estree-walker' (styleguidist#1349)

Because walkes has LGPL-3 license.

Fixes styleguidist#1210

Fix: Encode section pages URLs if a section name has special symbols (s…

…tyleguidist#1384)

Closes styleguidist#1332

Fix: Fix named export for example components (styleguidist#1380)

Closes styleguidist#1281

Fix: to make async/await work by default (styleguidist#1379)

Add transforms: { asyncAwait: false } for default compilerConfig to make async/await work by default. Bublé doesn't have transform for async/await so they raise an error if asyncAwait transformation in configuration is not false (true by default) since bublé v0.9.7.

Closes styleguidist#1371

Fix: Add .ts and .tsx to default extensions in webpack config

styleguidist#750

Fix: Allow section content to be function (styleguidist#1368)

Fix: A build should't break when assetsDir is an array (styleguidist#…

…1367)

copy-webpack-plugin is not allowed `from` to be as an array. If we still want to use `from` and support array format for assetsDir, then we should pass array of objects `{from: ...}` to the plugin.

Closes styleguidist#1320

Fix: Section anchors shouldn't conflict with component anchors (style…

…guidist#1364)

Prefix section anchors with `section-`.

Closes styleguidist#1342

Changelog: 🚀

## New features

### Support React Hooks in examples

You can now use hooks in the examples, like the `useState` hook:

 ```jsx
const [count, setCount] = React.useState(42);
<Button onClick={() => setCount(count + 1)}>{count}</Button>
```

(styleguidist#1353 by @eragon512)

## Bug fixes

* Accessibility fixes ([styleguidist#1359](styleguidist#1359) by @J-Kallunki)
* `getExampleFilename` should use default example if file does not exist ([styleguidist#1362](styleguidist#1362)) by @mendrew, closes [styleguidist#1338](styleguidist#1338)
* Hide HTML comments in Markdown files ([styleguidist#1347](styleguidist#1347) by @eragon512, closes styleguidist#1326)

Docs: Add styled-components with typescript example (styleguidist#1341)