add prettier for auto formatting (#231)

* [Prettier] Add "prettier"

Makes the formatting of the code consistent.
By using the eslint-plugin-prettier formatting issues will be highlighted as a lint error.
These errors will be auto fixed by running "lint --fix" (which can be done automatically on file save)

* [Prettier] Add "prettier" - Fix formatting

src/App.tsx

@@ -10,9 +10,7 @@ import CssBaseline from '@mui/material/CssBaseline';
 import AppContext from 'components/context/AppContext';
 import DefaultNavBar from 'components/navbar/DefaultNavBar';
 import React from 'react';
-import {
-    Redirect, Route, Switch,
-} from 'react-router-dom';
+import { Redirect, Route, Switch } from 'react-router-dom';
 import Browse from 'screens/Browse';
 import DownloadQueue from 'screens/DownloadQueue';
 import Extensions from 'screens/Extensions';
@@ -48,13 +46,7 @@ const App: React.FC = () => (
         >
             <Switch>
                 {/* General Routes */}
-                <Route
-                    exact
-                    path="/"
-                    render={() => (
-                        <Redirect to="/library" />
-                    )}
-                />
+                <Route exact path="/" render={() => <Redirect to="/library" />} />
                 <Route path="/settings/about">
                     <About />
                 </Route>
@@ -116,14 +108,7 @@ const App: React.FC = () => (
                 path="/manga/:mangaId/chapter/:chapterIndex"
                 // passing a key re-mounts the reader
                 // when changing chapters
-                render={(props: any) => (
-                    <Reader
-                        key={
-                            props.match.params
-                                .chapterIndex
-                        }
-                    />
-                )}
+                render={(props: any) => <Reader key={props.match.params.chapterIndex} />}
             />
         </Switch>
     </AppContext>