update readme (#4)

Author: michael-yin

.github/assets/code.png

@@ -11,25 +11,19 @@
 
 </div>
 
-```html
-{% load formify %}
-
-<form method="post">
-
-    {% csrf_token %}
-
-    {% render_form form %}
-
-    {% render_submit text='Hello Formify!' variant="primary" %}
-
-</form>
-```
+![Django Formify Code](.github/assets/code.png)
 
 ![Django Formify Demo](.github/assets/formify-demo.jpg)
 
 ## Documentation
 
+[Documentation](https://django-formify.readthedocs.io/)
+
 ## FAQ
 
 ### Django-Formify vs Crispy-Tailwind
 
+1. Django-Formify is a fork of Crispy-Tailwind, the core logic is the same.
+2. Django-Formify changed the way of rendering, to make it more flexible and easy to customize.
+3. Django-Formify has components built using Django-ViewComponent, which makes the code more reusable and easy to maintain. Developers can also create their own components to fit their needs.
+4. Django-Formify updated styles of some widgets such as file input to make them look better with Tailwind CSS.

README.md

@@ -11,6 +11,7 @@ Topics
 
    install.md
    get_started.md
+   tags.md
    formify_helper.md
    layout.md
    component_design.md

docs/source/index.rst

@@ -0,0 +1,47 @@
+# Template Tags
+
+## render_form
+
+This tag can render form or formset.
+
+It will iterate and render all form fields automatically.
+
+## render_submit
+
+This tag is to render the submit button.
+
+You can also add extra variables
+
+```html
+{% render_submit text='Sign In' css_class="custom-css" name='action_primary' value='action_primary' %}
+```
+
+`render_submit` behavior can be customized by overriding `formify_helper.render_submit` method
+
+Please check [Formify Helper](./formify_helper.md) to learn more.
+
+To use formify_helper attached to the `form` instance, you can pass `form` to the `render_submit` like this:
+
+```html
+{% render_submit form text='Hello' css_class="btn btn-primary" %}
+```
+
+If you have svg in submit button as indicator, you can use this approach to make your code DRY.
+
+## render_field
+
+In some cases, if you want to render a specific field, you can use this tag.
+
+```html
+{% render_field form.email %}
+```
+
+You can also override formify_helper variable like this:
+
+```html
+{% render_field form.email form_show_labels=False %}
+```
+
+## render_form_errors
+
+This tag can render form non-field errors.