Revert "docs: Improve Quick start instructions (#1458)"

This reverts commit 9a15ffb.

Author: sy-records

Diff for: docs/quickstart.md

@@ -81,7 +81,7 @@ If you prefer to lock docsify to a specific version, specify the full version af
 
 ### Manually preview your site
 
-If you have Python installed on your system, you can easily use it to run a static server to preview your site.
+If you installed python on your system, you can easily use it to run a static server to preview your site.
 
 ```bash
 cd docs && python -m SimpleHTTPServer 3000
@@ -97,7 +97,7 @@ If you want, you can show a loading dialog before docsify starts to render your
 <div id="app">Please wait...</div>
 ```
 
-By default, the `id` attribute of the main container is `app`. If you want to use a different id, you must also set the `data-app` attribute, and [configure](configuration.md#el) the `el` parameter accordingly:
+You should set the `data-app` attribute if you changed `el`:
 
 ```html
 <!-- index.html -->
@@ -110,3 +110,5 @@ By default, the `id` attribute of the main container is `app`. If you want to us
     }
   </script>
 ```
+
+Compare [el configuration](configuration.md#el).